Lesson 13: Vayishlach

From the book Mida Tova: Articles on the Principles of Halakhic Thinking by Rabbi Michael Avraham. Translated from Hebrew using gpt-5.4 (reasoning_effort=high, batch API).

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With God’s help

Concepts

Gezeirah (decree or command).

Formal warning: the textual and substantive definition of a prohibition as a negative commandment.

Abstract

In this article we begin with the prohibition of the sciatic nerve and show that every negative commandment requires an explicit warning in Scripture. This principle creates a difficulty with the sciatic nerve, since there is no verse that clearly warns against it. We propose two ways of reading the verse about the sciatic nerve and show that both are found among medieval authorities.

From this discussion we broaden the inquiry to the function of warning, and to its relation to terms such as mitzvah (commandment) and gezeirah. These issues are discussed in Maimonides’ eighth principle and in Nahmanides’ glosses there, where he also mentions the example of the sciatic nerve.

Our conclusion is that halakha (Jewish law) is built as a set of concentric spheres. There is a set of negative acts, that is, harmful and damaging acts, and positive acts, that is, reparative acts. Within this general normative sphere there is a halakhic sub-sphere that includes mitzvot, both positive and negative. Within the halakhic sphere there is a further sub-sphere of prohibitions formulated as negative commands, for which a formal warning is required. The warning is what defines an act as belonging to this inner sphere.

We connect this discussion to various essays in Midah Tovah that have dealt, and will deal, with this topic from additional angles.

The rules and principles that emerge from the article

On the sciatic nerve: a look at mitzvot and commands

General Introduction

In Parashat Vayishlah, the struggle between Jacob and the angel is described (Genesis 32:25-33):

Jacob was left alone, and a man wrestled with him until the break of dawn. When he saw that he could not prevail against him, he touched the socket of his thigh, and Jacob’s hip was dislocated as he wrestled with him. He said, “Let me go, for dawn has broken.” But he said, “I will not let you go unless you bless me.” He said to him, “What is your name?” And he said, “Jacob.” He said, “Your name shall no longer be called Jacob, but Israel, for you have striven with God and with men and have prevailed.” Jacob asked and said, “Please tell me your name.” But he said, “Why is it that you ask my name?” And he blessed him there. Jacob called the name of the place Peniel, “For I have seen God face to face, and my life has been saved.” The sun rose for him as he passed Penuel, and he was limping on his thigh. Therefore the children of Israel do not eat the sciatic nerve, which is on the socket of the thigh, to this very day, because he touched the socket of Jacob’s thigh at the sciatic nerve.

The angel touches Jacob’s hip socket and dislocates it. The passage ends by describing the fact that the children of Israel do not eat the sciatic nerve because the angel touched it. The Sages understood this as a standard halakhic prohibition. For example, in a midrash (rabbinic homiletic text) that describes how the commandments entered the world, from Adam to the giving of the Torah, the Sages say (see Shir Ha-Shirim Rabbah, parashah 1, s.v. “Rabbi Azariah,” and parallels):

Rabbi Azariah, and some say Rabbi Eliezer and Rabbi Yose son of Rabbi Hanina and the Rabbis: Rabbi Eliezer said, “This may be compared to a king who had a cellar full of wine. A first guest came; he poured him a cup and gave it to him. A second came; he poured him a cup and gave it to him. Once the king’s son arrived, he gave him the entire cellar. So too, Adam was commanded concerning seven commandments… To Noah there was added the prohibition of a limb from a living animal, as it is written, ‘Only flesh with its life, its blood.’ Abraham was commanded concerning circumcision. Isaac inaugurated it at eight days. Jacob was commanded concerning the sciatic nerve, as it is said, ‘Therefore the children of Israel do not eat the sciatic nerve.’ Judah was commanded concerning levirate marriage, as it is said, ‘Judah said to Onan: go in to your brother’s wife and perform levirate marriage with her.’ Israel received positive commandments and negative commandments…”

That is, the Sages understood this as a command to Jacob and his sons not to eat the sciatic nerve. Following them, the enumerators of the commandments did so as well, for example Sefer Ha-Chinukh, commandment 3, and likewise Maimonides in Sefer Ha-Mitzvot, negative commandment 183:

This commandment applies in every place and at every time, to males and females. One who transgresses it and eats one sciatic nerve, even if it is less than an olive-bulk, or who eats an olive-bulk from a large sciatic nerve, is flogged.

This is a full prohibition, and one who violates it is liable to lashes like one who violates any other ordinary negative commandment in the Torah. Indeed, to this day we excise the sciatic nerve as part of preparing an animal for kosher consumption.

A. The Sciatic Nerve

The Core Difficulty

We have seen that the Sages and the halakhic decisors view the sciatic nerve as a negative prohibition that carries lashes. But, as is well known, the Sages established a clear criterion for distinguishing verses of prohibition from other verses (see Babylonian Talmud, Menachot 99b, and parallels):

Rabbi Avin said in the name of Rabbi Ila’a: Every place where it says “beware,” “lest,” or “do not,” it is nothing other than a negative commandment.

The Talmud sees these formulations, and the medieval authorities added a fourth one as well, “not,” as the mark of a negative commandment. One might have said that if such language appears, then there is certainly a prohibition, but that its absence does not prove the opposite. Yet the standard understanding among the commentators is that this is a necessary condition, not merely a sufficient one. That also seems to follow from the continuation of that same talmudic passage, which concludes that when such formulations are doubled, there are two negative commandments:

Ravina said: “Beware” and “lest” are two negative commandments. Rav Nahman bar Yitzhak said: There are three negative commandments, as it is said: “Only take heed to yourself, and guard your soul greatly, lest you forget the things…”

If so, in the verse concerning the sciatic nerve, where no imperative language appears at all, it is unclear how one can identify a negative commandment. Now Sefer Ha-Chinukh writes, in commandment 3:

And this “they do not eat” was not stated by way of narrative, meaning that because this happened to the father, the children refrain from eating that nerve. Rather, it is the warning of the blessed God that they not eat it.

It seems that Sefer Ha-Chinukh understands the phrase “they do not eat” in the verse as command language. To be sure, this is not the plain sense of the verse, but perhaps he sees it as a kind of interpretive exposition. His source is probably the talmudic passage in Hullin 100b. In the Shir Ha-Shirim Rabbah passage cited above, we saw that the obligation begins with Jacob our forefather, but in fact this is the subject of a tannaitic dispute in the Mishnah in that very passage in Hullin:

Mishnah: It applies to kosher animals and does not apply to non-kosher animals. Rabbi Judah says: It applies even to non-kosher animals. Rabbi Judah said: But was not the sciatic nerve prohibited starting from the sons of Jacob, when non-kosher animals were still permitted to them? They said to him: It was stated at Sinai; it was only written in its place.

The tannaim disagree as to whether the prohibition of the sciatic nerve applies also to non-kosher animals or only to kosher ones. The root of the dispute is whether Jacob himself was commanded in this matter, in which case there was not yet any distinction between kosher and non-kosher animals, or whether this command was given only at Sinai, after that distinction already existed, and was merely written in the Torah here, within the story of Jacob and the angel. In the Gemara, Hullin 101b, from Tosefta 7:4, it is also stated that the expression “children of Israel” in the verse hints that the prohibition began at Sinai and not with Jacob.¹

According to the Sages, this very verse is the command, but it was displaced from its original setting in order to explain the reason for the prohibition, namely as a memorial to Jacob’s struggle with the angel. Sefer Ha-Chinukh there writes that the reason for the command is so that we not despair even in situations that seem hopeless to us, as in Jacob’s struggle with the angel. This was probably the source of Sefer Ha-Chinukh‘s understanding of the verse as a command and not as a description.

This is also how the Rashba explains it in his novellae to the aggadic material on Hullin 91a:

It is not a report… for if so it would follow that if Jacob had injured his leg, his sons would not eat legs, and so on. Rather, this is a command that they were instructed in by the Holy One, blessed be He.

So this verse is not a “report,” that is, a description, but a verse of command. It seems that according to these medieval authorities it thereby meets the criterion of “beware,” “lest,” and “do not.”

An Alternative Proposal

It follows that according to the Sages this verse is a command that was displaced from its place, but was given to us at Sinai and not to Jacob our forefather. According to Rabbi Judah, by contrast, this verse itself is the command, and it was given to Jacob himself.

The view of the Sages is problematic from the standpoint of the wording of the verse. The verse describes a practice; it is not formulated in command language. The issue is not only that a command has been moved from its place, from Sinai into the book of Genesis, but that the verse itself is styled as a description, a “report” in the Rashba’s language, rather than as a command. In fact, according to the verse, this practice is found among the children of Israel and not Jacob himself, which fits the Sages’ view that only Jacob’s descendants became bound by this prohibition at Sinai. According to Rabbi Judah, the wording of the verse is also problematic, since it describes not a command but a practice, and one must also explain why the verse says that only Jacob’s descendants observed this prohibition.

The statements of the Sages suggest another way to read the verse. The command given to Jacob does not appear in the verse at all. It is hidden behind the text, and the verse describes only the result of that hidden command: that Jacob, according to Rabbi Judah, or perhaps also his descendants, do not eat the sciatic nerve to this day. In that case, the verse describes a state of affairs that merely indicates the existence of a command; it does not itself contain the command. According to our proposal, the word “not” that appears in the verse is not imperative language at all, but straightforwardly descriptive.

A Halakhic Ramification of Our Proposal

The Gemara in Babylonian Talmud, Pesachim 22a discusses the relation between prohibitions of eating and prohibitions of deriving benefit. In the course of that discussion, a consequence is drawn with respect to the sciatic nerve:

Rabbi Abbahu said: Everywhere the Torah says “it shall not be eaten,” “you shall not eat,” or “you shall not eat them,” it implies both a prohibition of eating and a prohibition of deriving benefit, unless Scripture specifies otherwise, as it specifies in the case of carrion…

Rabbi Abbahu’s view is that the language of “eating” in the Torah is always interpreted as prohibiting both eating and deriving benefit, though Hezekiah disputes this in that passage. The Gemara there raises many objections against Rabbi Abbahu from various places. Among them is the case of the sciatic nerve:

Rabbi Yitzhak Nappaha raised an objection: But consider the sciatic nerve, regarding which the Merciful One said, “Therefore the children of Israel do not eat the sciatic nerve,” and yet we learned: A person may send a thigh to a gentile with the sciatic nerve inside it, because its place is recognizable. Rabbi Abbahu holds: When carrion was permitted for benefit, it and its fat and its sciatic nerve were permitted along with it. This works well according to the one who says that sinews impart flavor. But according to the one who says that sinews do not impart flavor, what can be said? Whom have you heard saying that sinews do not impart flavor? Rabbi Shimon. As it was taught: One who eats from the sciatic nerve of a non-kosher animal, Rabbi Judah obligates him twice, and Rabbi Shimon exempts him. Rabbi Shimon would likewise hold that it is prohibited for benefit, as it was taught: The sciatic nerve is permitted for benefit, according to Rabbi Judah, and Rabbi Shimon prohibits it.

Rashi explains there that it follows from this passage that the sciatic nerve is permitted for benefit because Scripture treated it like carrion. However, in Mahara Polda and Korban Ha-Edah on Jerusalem Talmud, Orlah 3:2 and Pesachim 2:1, we find the view that only the sciatic nerve of an actual carcass was permitted for benefit, not every sciatic nerve. See also Torah Shelemah on our passage, sec. 158.

In any event, even according to Rashi and those who follow him, the talmudic discussion implies that permission to derive benefit from the sciatic nerve depends on the view that sinews impart flavor. If sinews do not impart flavor, then the nerve does not absorb the flavor of carrion. The Gemara in Hullin 101a refers to the nerve as “wood,” that is, as something hard that neither absorbs nor counts as meat. It is therefore not itself considered part of the carrion, and the Torah did not permit benefit from it. Only according to the view that sinews impart flavor did the Torah permit benefit from it. Most medieval authorities assumed this.

But Maimonides rules that sinews do not impart flavor, in Mishneh Torah, Forbidden Foods 15:17; see also 4:18, and nevertheless he permits deriving benefit from the sciatic nerve there as well, 14:14 and 14:16. Many commentators went on at length in objecting to him; see, for example, the Rosh on Hullin, chapter 7, sec. 17, in the name of the scholars of Lunel, and Minhat Hinukh, commandment 3, sec. 11, among many others. Yet we do find other approaches like this. For example, Nahmanides, in a responsum cited in the Rashba’s Torat Ha-Bayit, Third House, Third Gate, explained that the linkage the Gemara makes between these two laws is not a real dependence, but only a convenient way of framing the discussion.

We suggest that the explanation of Maimonides and Nahmanides is that the verse does not itself command the prohibition of the sciatic nerve. It only hints indirectly to the existence of such a prohibition. Therefore Rabbi Abbahu’s rule in Pesachim, that wherever the Torah uses the language of “eating” it means both a prohibition of eating and a prohibition of deriving benefit, does not apply here. There is no command here that prohibits eating. There is only a description that Israel do not eat the sciatic nerve. Rabbi Abbahu’s rule speaks only about verses of command; it does not define the word “eating” as such.

If so, the sciatic nerve is permitted for benefit even according to Rabbi Abbahu, and according to all views. The give-and-take in the Gemara proceeds on the assumption that the verse commands a prohibition of eating, but Maimonides interprets and rules otherwise. The permission to derive benefit is therefore not based on the fact that sinews do not impart flavor and not on a source from carrion, but simply on the absence of any source to prohibit benefit, since the description speaks only of eating.²

Our discussion shows that the way one reads the verse can affect concrete halakhic questions. The scholars of Lunel understood the verse as did Sefer Ha-Chinukh and the Rashba, and therefore assumed that it contains command language regarding eating the sciatic nerve. Maimonides and Nahmanides, by contrast, understood it along the lines we have suggested.

An Implication for What Was Stated and Repeated at Sinai

There is a rule that a command stated before the giving of the Torah and not repeated at Sinai was said only to Israel. If it was repeated at Sinai, then it was said both to Israel and to the descendants of Noah. See our essay on Parashat Noach, 2007. What, then, is the law regarding the sciatic nerve? We find in Babylonian Talmud, Sanhedrin 59a:

Rabbi Yose son of Rabbi Hanina said: Every commandment that was stated to the descendants of Noah and repeated at Sinai was said to both these and those. If it was stated to the descendants of Noah and not repeated at Sinai, it was said to Israel and not to the descendants of Noah. And we have only the sciatic nerve, and that only according to Rabbi Judah.

This makes it clear that according to Rabbi Judah the command was stated to Jacob’s sons, whereas according to the Sages it was stated only to Moses at Sinai and copied into this earlier context. But even according to Rabbi Judah a difficulty remains. Seemingly, this statement implies that the reason the command binds only Israel, according to Rabbi Judah, is that it was stated to Jacob and not repeated at Sinai. This is the only example the Talmud finds of such a phenomenon. But the exclusivity of the prohibition to Israel seems to arise from the wording of the command itself, not from the fact that it was stated only before Sinai. After all, the verse itself says that “the children of Israel” do not eat the sciatic nerve; see Rashi here. If so, how can the Gemara present the sciatic nerve, according to Rabbi Judah, as an example of a commandment that was stated to the descendants of Noah and not repeated, and is therefore valid only for Israel?

According to our approach, the matter is easier. We suggested that this verse is not a command verse at all. Therefore, even according to Rabbi Judah, the commandment was not necessarily stated only to Jacob’s sons. The verse merely describes the fact that Israel observe this prohibition, but it remains entirely possible that the command itself was given to all the descendants of Noah. Indeed, in Hullin 91a it is clear that there is an opinion that the sciatic nerve was prohibited even to the descendants of Noah. Rashi there explains that the meaning is that it was prohibited to Jacob’s sons while they were still descendants of Noah, and see also Tosafot, s.v. “Kodashim,” Hullin 90a.³ On our reading, however, there is no need for this, and the Gemara may be read in its plain sense.

Maimonides, too, in his Commentary on the Mishnah to Sanhedrin, writes against Rashi. In his view, even the Sages agree that Jacob had already been commanded in this matter, but we observe the prohibition because of the command at Sinai, not because of the command to Jacob. See Torah Shelemah here, sec. 160, which objects to him from several passages that appear to say the opposite. According to our proposal, one could say that Maimonides means that the command was not given to Jacob in the Torah’s explicit wording, but only alluded to there, and therefore what binds us is only the fact that it was repeated at Sinai. According to the Sages, that is the context in which this descriptive verse was written.

B. Can There Be a Prohibition without an Explicit Source?

Introduction

In the previous section we raised the possibility that the command concerning the sciatic nerve does not appear explicitly in the Torah at all, but is only described there indirectly. Can there be a binding halakhic prohibition without an explicit source in the Torah? Is the rule of “beware,” “lest,” and “do not” not a necessary criterion for the existence of a negative commandment? In this section we will touch briefly on this fundamental and important question.

Head Covering

We know other examples of indirect indications of prohibitions. For example, in the section of the suspected adulteress, the Torah says, “And he shall uncover the woman’s head” (Numbers 5:18). From this the Sages learn that married women are obligated to cover their hair, as stated in Babylonian Talmud, Ketubot 72a:

And what is “Jewish practice”? Going out with her head uncovered. But an uncovered head is a matter of Torah law. As it is written, “And he shall uncover the woman’s head.” And a tanna from the school of Rabbi Ishmael taught: This is a warning to the daughters of Israel that they should not go out with uncovered head.

Here no word of warning appears at all, neither “beware,” nor “lest,” nor “not,” nor “do not,” yet the Sages learn from this a Torah prohibition against going out with one’s hair uncovered.

It should be stressed that this example is even more extreme than the case of the sciatic nerve. In the case of the sciatic nerve, a prohibition of eating is clearly described, but in the form of description, a “report” in the Rashba’s language, and not a command. Here there is not even a hint of an obligation to cover the head, except perhaps that women customarily covered their hair.⁴ We should note that in the course of the talmudic discussion, the objection from this verse is directed against the Gemara’s claim that a woman’s uncovered head is a matter of “Jewish practice,” which Rashi explains there as follows:

Jewish practice: what the daughters of Israel have customarily observed, even though it is not written.

That is, the verse proves that this is not merely an unwritten custom, but Torah law. But does the verse really prove that?

Rashi interprets the proof from the verse in two ways:

Warning: because we do this to her in order to disgrace her, measure for measure, just as she adorned herself for her lover; from this it follows that it is forbidden. Alternatively, from the fact that it is written “and he shall uncover,” it follows that until that moment her head was not uncovered. From this learn that it is not the way of the daughters of Israel to go out with uncovered head, and this is the main explanation.

The first direction learns from the content of the act itself. On that reading, this is an interpretive derivation without an explicit warning in the verse: from the fact that we uncover the head of a wayward woman, it is evident that an uncovered head is associated with waywardness. The second direction, which Rashi regards as primary, derives the point by inference, as we suggested above.

Generalization: Maimonides in the Eighth Principle

We find a principled discussion of command language and related formulations in the eighth principle of Maimonides, where he deals with negations. I will cite several passages from his words and then discuss his disputes with Nahmanides in the latter’s glosses there.

Maimonides’ basic definition divides commands into positive and negative commandments:

The eighth principle is that it is improper to count simple negations together with warnings. Know that a warning is one of the two parts of command. For you command the one addressed either to do something or not to do it. Thus, you may command him to eat and say, “Eat,” or you may command him to refrain from eating and say, “Do not eat”… The well-known Arabic particle used for warning is la. This same matter certainly exists in every language. That is, you command the addressee to do something or not to do it. It is therefore clear that positive commandments and negative commandments are both complete commands: matters He commanded us to do and matters He warned us not to do. What we are commanded to do is called a positive commandment, and what we are warned away from is called a negative commandment. The general term that includes them both in Hebrew is gezeirah. Thus the Sages called every commandment, whether positive or negative, “the King’s decree.”

Maimonides then points out that in Hebrew this same word “not” also appears in another, non-normative meaning, one that does not belong to the categories of commandments and decrees. In the course of his remarks, he notes that Arabic has a separate word for non-normative negation:

But simple negation is something else: you deny a predicate of a subject, and there is nothing of command in it at all. For example: “So-and-so did not eat last night,” “So-and-so did not drink wine,” “Reuben is not Simeon’s father,” and the like. All of this is simple negation, with not a trace of command in it. In Arabic, the word most often used for negation is ma. They also negate with la and with laysa. But in Hebrew, most negation is with the very word “not,” the same word by which warning is expressed. Hebrew also negates with “there is no” and the pronominal forms attached to it, such as “he is not,” “they are not,” “you are not,” and the like. Negation in Hebrew with “not” appears in verses such as “Never again did there arise in Israel a prophet like Moses,” “God is not a man, that He should lie,” “Affliction shall not rise a second time,” “No man stood with him,” “He arose and did not tremble before him,” and many others. Negation with “there is no” appears in verses such as “and there was no man,” “the dead know nothing,” and many others.

He then proceeds to draw conclusions from this distinction for the enumeration of the commandments:

The difference between warning and simple negation has now become clear. Warning belongs to the category of command, and therefore it exists only in the verbal mode of command. Just as command always concerns the future, so does warning. Language does not allow command in the past, and the same is true of warning. There is no way to insert command into narrative, for narrative requires a predicate and a subject, whereas command is a complete utterance, as has been explained in the books written on this subject. Warning, too, cannot be inserted into narrative. Negation is not so, for negation can enter narrative and can negate the past, the future, and the present. All this is self-evident to anyone who reflects.

Since this is so, prohibitions that are mere negations should in no way be counted among the negative commandments. This is a self-evident matter that needs no proof beyond what we have said about the meanings of the words, sufficient to distinguish warning from negation.

This principle, that verses whose function is negation rather than warning should not be counted, seems to Maimonides entirely obvious and in no need of proof or justification. Even so, he thinks that Halakhot Gedolot erred on this point, and he brings several examples that should not have been counted, as well as several that Halakhot Gedolot itself did not count:

This escaped some of our predecessors, to the point that he counted “she shall not go out as the slaves go out,” not realizing that this is negation and not warning. I will explain this… There is no difference between “she shall not go out as the slaves go out” and “the priest shall not inspect the yellow hair; it is unclean,” which is only negation and not warning. It tells us that in the presence of this sign there is no need for quarantine and no room for doubt, because it is unclean.

Likewise, “they shall not be put to death, because she was not freed” is also negation and not warning, for it means that they are not liable to death because her emancipation was incomplete. It should not be interpreted as “they shall not be put to death” in the sense of warning… Likewise, “and he shall not be as Korah and his congregation” is a negation. The Sages explained that it is a negation and interpreted it to mean that the Blessed One told us that anyone who disputes the priesthood and stirs up controversy over it will not undergo what befell Korah and his congregation, namely swallowing and burning, but rather his punishment will be what the Lord spoke by the hand of Moses, namely leprosy, as is shown by what happened to Uzziah king of Judah…

He then sums up, and explicitly connects the principle of this section to the talmudic rule of “beware,” “lest,” and “do not,” which we cited above:

I have explained this matter with complete clarity, so that no doubt remains, not even for the dullest mind among men. After speaking with this intention, know that there are four words in the Torah by which warning comes. Whatever the Torah warns against by one of these four is called a negative commandment. They are: hishamer, pen, al, and lo. And they said explicitly: every place where it says hishamer, pen, and al, it is nothing other than a negative commandment.

Up to this point, then, Maimonides states categorically that negations cannot be counted among the 613 commandments, because they are descriptions and not commands. At first glance, this seems to contradict what we saw above with regard to the sciatic nerve, where the verse is a description, or a “report,” and yet the prohibition is counted among the commandments. In fact, one wonders why Maimonides does not mention the sciatic nerve at all as an example relevant to this principle.

And Yet: A “Not” That Is Descriptive but Not Mere Negation

At the end of this principle, however, Maimonides writes the following:

One point still remains to be explained so that the purpose of this section may be complete. When the Torah recounts something and decrees for us that we should purify ourselves by negating from ourselves a certain act or acts, then that act is counted among the negative commandments, even though the “not” that appears there is negation and not warning. Since we were commanded to negate that act from ourselves and to say, “I did not do such-and-such,” we know necessarily that such-and-such an act is prohibited. This is like the verse that commands us to say, “I have not eaten of it in my mourning, I have not destroyed any of it while impure, and I have not given any of it for the dead.” This shows that each of these acts is prohibited. The explanation of this will come in its proper place, in our discussion of these commandments.

Maimonides gives here several examples of words of negation that appear in the sense of negation rather than warning, and yet they indirectly testify to the existence of a warning. For example, the declaration recited in the Temple, “I have not eaten of it in my mourning,” testifies that there is a prohibition against eating it in a state of mourning, or against destroying it while impure, or against giving it for the dead. So although there is no warning language here, the negative description indirectly testifies to the existence of a prohibition, and in that sense it functions as a warning.

It seems that Maimonides does not mean that the word of negation itself is the warning. Even a description that contains no negating word can serve as an indirect indication of a prohibition. This is precisely our point in the proposal above concerning the interpretation of the verse about the sciatic nerve.

Nahmanides’ Objection and His Basic Approach

In his gloss on the eighth principle, Nahmanides agrees with Maimonides’ basic point, and even cites a source from the Sages for it:

In the eighth principle the Rabbi, of blessed memory, said that negations should not be counted together with restraints. The Rabbi explained this principle and the matter of negations, where one denies a predicate of a subject and there is nothing of command in it at all. He also said that the Sages, peace be upon them, already testified to this matter in their dispute regarding one of the prohibitions, namely the verse about the bird sin-offering: “and he shall pinch off its head opposite its neck, but he shall not separate it.” The tanna of our Mishnah expounded that if he separated it, he invalidated it, and in his opinion this is a restraint. Rabbi Elazar son of Rabbi Shimon expounded: he need not separate it. In his view, then, it is negation and not restraint. All these matters are clear and not hidden from any understanding person, even a student.

Immediately afterward, Nahmanides states that the Torah does not ordinarily use negative wording in a non-normative sense, except in unusual cases where there is some redundancy in the verse:

But we must add one further condition. According to our Rabbis, there is nothing in the Torah that is said in the language of prohibition or the language of command and is merely a negation of a command, that is, permission, or merely a negation of one of the laws, unless the verse actually requires that negation. Thus, in that dispute, according to the sage who sees “and he shall not separate it” as negation, they said in Zevahim 66a: Since it is already written “and he shall bring it,” the verse has already distinguished between the bird sin-offering and the bird burnt-offering. Why then do I need “he shall not separate it”? Learn from this that he need not separate it.

Nahmanides thus holds that a verse should be interpreted as simple negation only when, even without that negation, we would not have thought the matter prohibited. On the basis of this principle he explains the count in Halakhot Gedolot: all the negations it counts as commandments are cases where the negative wording must be read as a prohibition, not as simple negation, because there is no redundancy that would justify the latter reading.

It should be noted that Nahmanides is consistent here with his broader method. In the fifth principle as well, he is unwilling to interpret verses as reasons for commandments except in exceptional cases. Ordinarily, in his view, the Torah is concerned only with commandments. In the ninth principle we find a similar dispute between him and Maimonides with regard to repetitions in the Torah: Maimonides sometimes sees them as merely literary devices, whereas Nahmanides insists that each appearance of a given commandment in the Torah must carry halakhic meaning.

Nahmanides on Indirect Indications of Prohibitions: No Punishment without Warning

Nahmanides then cites Maimonides’ closing paragraph about indirect indications of prohibitions and notes that Halakhot Gedolot also seems to agree with that principle. He himself, however, rejects it emphatically:

But what the Rabbi wrote, that when we are commanded in the Torah to negate from ourselves a certain act or acts, that act should be counted among the negative commandments, even though the “not” that appears there is negation and not restraint, as in the verse “I have not eaten of it in my mourning, I have not destroyed any of it while impure, and I have not given any of it for the dead,” and the author of Halakhot Gedolot also agreed to this, I never accepted this criterion. For it seems from the words of our Rabbis in the Talmud that there is no prohibitive injunction in the Torah for which lashes are given that comes by implication. Rather, these and the like are a prohibition inferred from a positive commandment: we who are alive were positively commanded to eat it in purity before the Lord and in joy, not in mourning, not in impurity, and not to give any of it for the dead.

According to Nahmanides, there is no indirect warning in the Torah at all. Everywhere there is a genuine negative commandment, the Torah must command and warn us explicitly, in a verse that functions as a prohibition and not in verses of mere negation. Nahmanides seems to view this as an extension of the principle that there is no punishment unless there was prior warning. Without an explicit warning in the Torah, punishment cannot be imposed. Therefore, wherever there is only an indirect indication of a prohibition and no warning, that cannot count as a warning. At most it is a prohibition inferred from a positive commandment, which is legally treated as a positive commandment. For example, one who burns oil of the second tithe that became impure is not flogged, because this is not a negative commandment but a prohibition inferred from a positive commandment, which is effectively a positive commandment. Nahmanides then goes on to prove this claim at length, but that lies beyond our scope here.

Thus, according to Nahmanides, there cannot be a halakhic negative prohibition for which we have no warning in one of the standard formulations recognized by the Sages. If there is no warning, there cannot be a negative commandment. There may still be a prohibition that carries no punishment, such as a prohibition inferred from a positive commandment, but not a negative commandment. A negative commandment requires warning, because our accepted rule is that there is no punishment unless there was prior warning.

Nahmanides’ Explanation of the Warning for the Sciatic Nerve

The problem that now arises in light of Nahmanides’ position is how we are to understand the verse about the sciatic nerve. At first glance, that verse seems to be simple negation and not warning. According to his method, we ought therefore to treat it at most as a prohibition inferred from a positive commandment, which is effectively a positive commandment, that is, one for which lashes are not given, if it even counts as a prohibition at all. In fact, perhaps there would be no reason to see any prohibition there at all, since it is only a description of a custom. Yet, as we saw, in halakhic practice everyone agrees that we treat it as a negative commandment, and that one who eats the sciatic nerve is flogged.

Now, in the course of his discussion, when Nahmanides considers whether “and he shall not be as Korah and his congregation” is warning or negation, he mentions the verse of the sciatic nerve in passing and writes:

But the plain meaning and principal sense of the verse is that through the hammered plates used as a covering for the altar, Scripture commanded a memorial for the children of Israel in two matters: that no outsider should approach to burn incense and offer a sacrifice, and likewise that no person should dispute the priesthood of Aaron by saying that it was not from the Lord. Both of these, although stated by way of memorial, are prohibitions, like “therefore the children of Israel do not eat the sciatic nerve,” and like “it shall not be worked with and it shall not be sown.” “No outsider shall approach” is not counted because there is another explicit prohibition concerning all service in the Sanctuary, namely “and no outsider shall approach you.” But “and he shall not be as Korah and his congregation” is counted, as we explained.

It is not entirely clear what Nahmanides means here. At first glance, he seems to mean that this is a verse of warning rather than negation, though cast in historical form. Yet his language suggests that the verse is stated “by way of memorial,” that is, as a negation and not as warning. On the other hand, although it is stated “by way of memorial,” it is in effect still a prohibition, that is, a full legal negative commandment.

It seems, then, that Nahmanides means what we suggested above: this verse is not itself a verse of warning, but only an indication of the existence of a warning. When a verse clearly indicates that there is a warning, that is enough to count as warning and to justify punishment. But this raises a further question: why are other negations, such as “I have not eaten of it in my mourning,” not sufficient to create a negative commandment? There too there is an indirect indication of a prohibition. Why is the indirect warning found in the sciatic nerve different?

An Indication of a Warning and an Indication of a Prohibition

We are forced to conclude that according to Nahmanides, in the case of eating the second tithe in impurity there is only an indirect indication of the existence of a prohibition, but not of the existence of a warning. In contrast, in the case of the sciatic nerve there is an indirect indication, a “report,” of the existence of a warning, and therefore one can derive from it a full legal negative commandment and even punish its violation with lashes.

The assumption behind this claim is that “warning” and “prohibition” are not synonymous terms. We already see this in Nahmanides himself, for he is willing to recognize certain biblical prohibitions even when there is no clear warning, but not as negative commandments. Rather, they are only prohibitions inferred from positive commandments and the like. If so, Nahmanides does not require an explicit warning as a condition for establishing a biblical prohibition as such. It is a condition for punishment, that is, a condition for establishing a negative commandment, not for establishing a prohibition.

Accordingly, when the Torah wants to warn us by way of a negative commandment, a warning is required. It is not enough to inform us that something is forbidden. Warning is a formal requirement that differs from mere notification of a prohibition. The novelty of our proposal is that even Nahmanides does not require an explicit warning in Scripture. He requires only that it be clear that a warning exists. In his view, clarity that a prohibition exists is not equivalent to clarity that a warning exists.

“I have not eaten of it in my mourning” testifies that some prohibition exists, but we have no indication that it is a negative commandment. It may be a prohibition inferred from a positive commandment, or some other lighter form of prohibition. Therefore that verse is not enough to define a negative commandment. But the verse about the sciatic nerve testifies to the existence of a warning, not merely to the existence of a prohibition. Why, indeed, does it testify to a warning? This can be understood in two ways:

1. In terms of content. When the Torah describes a prohibition against eating the sciatic nerve, it is clear that this is a regular negative commandment, for it is implausible that there is a positive commandment to search out the nerve and remove it, and that the eating prohibition is only inferred from that. The relationship is clearly the reverse: the duty to search for and remove the nerve is derived from the prohibition of eating it. Therefore this is not a prohibition inferred from a positive commandment, but an ordinary negative commandment.
2. In terms of textual context. “I have not eaten of it in my mourning” is a description spoken by the pilgrim. By contrast, “therefore the children of Israel do not eat the sciatic nerve” is a description spoken by the Torah itself. Such a description is understood by Nahmanides as indicating the existence of a warning, and not merely the existence of a prohibition.

Two Dimensions in Every Commandment and Transgression

What, then, is the real difference between a prohibition and a warning? What does a negative commandment contain that another kind of prohibition does not? Why, in order to prohibit something as a prohibition inferred from a positive commandment, is it enough to notify us that it is forbidden, whereas in order to prohibit it as a negative commandment a warning is required? What is present in that “warning” beyond the mere information that a prohibition exists? Here we can offer only an introduction to this important discussion.

In our essay on Parashat Lekh Lekha, 2007, in the discussion of the provisional guilt offering, we cited Rabbi Elchanan Wasserman’s remarks in his essay “Repentance,” included in Kovetz Ma’amarim. He notes that every halakhic mitzvah or prohibition has two different dimensions: obedience or rebellion, and repair or corruption. One who commits a transgression thereby does two things: he rebels against the command of the Torah, and he damages or mars something in the world or in the person, for it was precisely to prevent that damage that the prohibition was given. The same is true of one who performs a mitzvah: he obeys the command of the Torah, and he repairs something in the world or in the person, for that is why the commandment was given.

When the Torah informs us that a certain act is harmful, to us or to the world, it is of course clear that it expects us not to do it. But there is not yet a command here. Therefore, in such a case, one who violates this prohibition does not rebel against a command of the Torah, because no command was issued. In that case there is only the dimension of damage, whether in the world or in the person. If so, in order to establish a halakhic prohibition, it is not enough for the Torah to inform us that a given act damages the world or the person; it must warn us not to do it.

At first glance, the warning is simply the command itself. A “report” is only the factual revelation that some act is problematic, or conversely that some act is beneficial and good. But in order to enter the halakhic sphere, what is required is a command, not merely factual information. The command establishes an obligation to obey and a prohibition against rebelling, which is the second dimension present in every halakhic commandment or transgression.

Between Command, or Gezeirah, and Warning

But this explanation is not sufficient. The criterion of command is needed in order to define an act as belonging to the halakhic sphere at all; see our essay on Parashat Vayera, 2007. Here, however, we are dealing with a distinction that lies entirely within the halakhic sphere: between a halakhic prohibition that carries a warning and a halakhic prohibition that does not. We are looking for a sub-sphere within the halakhic sphere, the sphere of warnings. What characterizes it? What is unique about it in contrast to other kinds of prohibition? Is it the fact that violation is punishable? Or do all negative commandments belong to this sphere? From Nahmanides’ words cited above, it follows that warning is required in order to establish a negative commandment, and not only in order to punish. For otherwise we could have defined eating second tithe in impurity as a negative commandment that does not carry lashes because it lacks warning. Nahmanides says that it is a prohibition inferred from a positive commandment. That means that he requires warning for every negative commandment, not only for one that carries punishment.

If so, Rabbi Elchanan Wasserman’s analysis defines the concept of command, but not the concept of warning. There is something in the notion of warning beyond what there is in the notion of command. This seems to be Maimonides’ intent in the passage from the eighth principle cited above, where he writes that the term gezeirah is common to both positive and negative commandments, whereas Arabic uses separate terms for the two. Gezeirah is the layer about which Rabbi Elchanan Wasserman speaks. Our present discussion is located within the halakhic sphere, and we are trying to define the distinction between a negative and a positive commandment, in a way that will distinguish between the sphere of command and the sub-sphere of warning.

In our essay on Parashat Vayetze, 2007, we considered Nahmanides’ attempt to distinguish between negative and positive commandments and some halakhic consequences of that basic distinction. There was not enough room there for an exhaustive discussion of the relation between negative and positive commandments, and of the halakhic and meta-halakhic definition of one as against the other. The clarification of that difficult issue, in light of Nahmanides’ remarks here and those of other medieval authorities, will continue, God willing, in a future essay. Only there will the discussion begun in this essay be completed.

Let us also note that in next week’s essay we will take an important step toward distinguishing among several kinds of command and obligation, and toward understanding the concept of mitzvah. There too we will define several sub-spheres within the general halakhic sphere.

Summary

Our conclusion is that the normative world is built as a set of concentric spheres. There is a body of norms, that is, negative acts, harmful and damaging acts, and positive acts, reparative acts. Within this general normative sphere there is a halakhic sub-sphere, which includes commandments, both positive and negative. The command, or gezeirah in Maimonides’ terminology, defines that sphere. Within the halakhic sphere there is a further sub-sphere of prohibitions formulated as negative commandments. The warning is what defines a given act as belonging to this inner sphere. It makes punishment of the violator possible, but as we noted, the role of warning is distinctive already at the level of defining the prohibition as a negative commandment, and not only at the level of punishment for violating it.

Footnotes