Shemini (5764)

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

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With God’s help. Midah Tovah — Eve of the holy Sabbath, Parashat Shemini 5765

Questions

1. Is there a kal va-homer based on only two data points?
2. In every kal va-homer, is the derived case more stringent than the source case, or the reverse?
3. Kal va-homer as a textual hermeneutic principle.
4. Is what is written in the Torah more stringent than what is not written in it?
5. Does every kal va-homer cut off the branch on which it sits?
6. Absence of information and irrelevance of parameters.
7. Why do we not derive a kal va-homer from a halakha le-Moshe mi-Sinai?

The Hermeneutical Principle: Kal va-Homer (A Fortiori Inference)

Aaron lifted up his hands toward the people and blessed them; and he came down from offering the sin offering, the burnt offering, and the peace offerings. Moses and Aaron entered the Tent of Meeting, and they came out and blessed the people, and the glory of the Lord appeared to all the people.

— Leviticus 9:22-23

“And Moses and Aaron entered the Tent of Meeting” — why did Moses and Aaron enter together? Was it to teach Aaron the rite of the incense, or did they enter for some other matter? I reason as follows: coming down requires a blessing, and entry requires a blessing. Just as going out [apparently, the text should read: coming down] was akin to the service, so too entry was akin to the service. From where do we know that entry requires a blessing? It stands to reason: if exit, which does not require washing, nevertheless requires a blessing, then entry, which does require washing, is it not all the more so that it requires a blessing? Or perhaps the reverse: if entry, which does not require a blessing, nevertheless requires washing, then exit, which does require a blessing, is it not all the more so that it requires washing? No: if you say this of entry, that is because one passes from the profane to the holy; will you say the same of exit, where one passes from the holy to the profane? The reversal is therefore nullified, and we return to the original argument: coming down requires a blessing, and entry requires a blessing. Just as coming down was akin to the service, so too entry was akin to the service. Why, then, did Moses enter with Aaron? To teach him the rite of the incense.

— Sifra, Shemini, parashah 1

A. Is There a Kal va-Homer Based on Only Two Data Points?

Introduction

In the past we distinguished among three kinds of midrash (rabbinic interpretation): midrash halakha (legal exegesis), midrash aggadah (homiletical interpretation), and interpretive midrash. The midrash cited above is an interpretive midrash, because its goal is to uncover the plain sense of the verses. The verses are not dealing with narrative elaboration, nor does the exposition create stories around them. The consideration at work in the midrash is halakhic, but its goal is to uncover what happened, not necessarily what obligates us.

The interpreter here uses the principle of kal va-homer, but in a strange form: it is a kal va-homer based on only two data points. We will try to clarify the exposition, and through it open up several interesting and fundamental insights about kal va-homer in general.

The Course of the Midrash

The midrash seeks to determine why Moses and Aaron entered the Tent of Meeting: was it to teach Aaron the service of the incense, or for some other reason? To resolve this, the midrash begins by learning from “coming down” to “entry” — since both require a blessing — and concludes that entry into the Tent of Meeting was also akin to an act of service, that is, it was done for the sake of learning the incense rite.

At this point the midrash begins to ask: how do we know at all that entry requires a blessing? To understand the question, one must pay attention to the verses cited above. Verse 22 makes clear that descending from the altar requires a blessing, and verse 23 makes clear that exit requires a blessing. It is not clear whether entry also required a blessing, in which case the blessing mentioned in verse 23 describes both the entry and the exit, or whether that blessing refers only to the exit and not to the entry.

To determine how we know that entry, too, requires a blessing, the midrash performs a kal va-homer: if exit, which does not require washing, nevertheless requires a blessing, then entry, which does require washing, surely requires a blessing. Immediately afterward, however, the midrash raises the exact opposite possibility: to learn from entry, which does not require a blessing and yet does require washing, to exit, which does require a blessing and therefore surely requires washing.

The decision between these two opposing possibilities — below we shall explain what exactly the opposition is — is made on the basis of conceptual reasoning: entering from the profane into the holy calls for a blessing more than exiting from the holy into the profane does, and therefore it is clear that entry requires a blessing. Once that is established, one can return to the first formulation of the kal va-homer. As stated, from here the midrash proves that the entry into the Tent of Meeting was for the sake of teaching the rite of the incense.

The Structure of This Kal va-Homer

Previously, for example in the page on Parashat Noah, we became acquainted with three types of kal va-homer:

1. A kal va-homer of the “if two hundred, certainly one hundred” type, which assumes one datum and derives the conclusion necessarily.
2. “All the more so,” which is a kal va-homer that assumes one datum and reaches the conclusion by means of reasoning, though it remains open to refutation.
3. A hermeneutical kal va-homer with three data points, from which the fourth can be inferred.

Our midrash contains a new kind of kal va-homer, one based on only two data points. In our example, the two data points are that entry requires washing and that exit requires a blessing. By means of the kal va-homer we seek to determine a certain halakhic conclusion — here, whether entry requires a blessing. What is the logic of this kind of kal va-homer? It is quite clear that this is a different type altogether.

The Structure of a Hermeneutical Kal va-Homer

A hermeneutical kal va-homer may be presented as a 2×2 table. The number of data points in the kal va-homer is the number of filled cells in the table, as follows:

State/action	Washing	Blessing
Entry	+
Exit		+

The purpose of every kal va-homer is to fill in the empty cells of the table. Let us now discuss several possible cases:

1. If we were given that exit does not require washing, then this would be an ordinary hermeneutical kal va-homer. We would have three data points in the table, and from them we could infer that entry requires a blessing. The reasoning would be: if exit, which does not require washing, nevertheless requires a blessing, then entry, which does require washing, surely requires a blessing.
2. If we were given the opposite datum, namely that entry does not require a blessing, then once again we would have an ordinary hermeneutical kal va-homer. We would have three data points in the table, and from them we could infer that exit requires washing. The reasoning would be: if entry, which does not require a blessing, nevertheless requires washing, then exit, which does require a blessing, surely requires washing.

It is important to notice that these two kal va-homer arguments contradict one another. In the first, we assume as a datum that exit does not require washing. But the conclusion of the second is that exit does require washing. And vice versa: in the second we assume that entry does not require a blessing, whereas the conclusion of the first is that entry does require a blessing. The conclusion of each argument undermines the basis of the other, and vice versa.

A Two-Data-Point Kal va-Homer: First Problem — Internal Contradiction

What happens when we have only two data points? Seemingly, one could fill in either of the missing data and then perform a kal va-homer. But as we have seen, the conclusions of these two arguments would contradict each other. More than that: it is not even clear how we are supposed to fill the two empty cells. The fact that the Torah teaches us nothing about them leaves them open. We cannot mark them either with “-” or with “+.” Therefore, in such a case it would seem impossible to perform either of the two kal va-homer arguments above.

If so, not only do the two arguments contradict one another; it seems that each one, taken on its own, is unjustified.

A Two-Data-Point Kal va-Homer: Second Problem — Absence of an Axis of Comparison

There is another problem with a kal va-homer that has only two data points, and several writers on the rules of interpretation have already noted it. Let us take an absurd example brought in Rabbi Ostrovsky’s book: if a doorpost, which is subject to mezuzah, is not subject to tzitzit, then a four-cornered garment, which is not subject to mezuzah, should all the more so be exempt from tzitzit. And conversely: if a four-cornered garment, which is obligated in tzitzit, is exempt from mezuzah, then a doorpost, which is exempt from tzitzit, should all the more so be exempt from mezuzah.

The problem here is that there is no exemption of mezuzah from tzitzit; rather, there is simply no obligation stated here. In other words, the obligation of tzitzit does not pertain to doorposts. They are not exempt from it; they simply do not belong to its domain of application.

Let us illustrate this with a logical analogy. The statement “virtue is triangular” is not false, and certainly not true either. It is a statement lacking sense and meaning. The reason is that virtue does not lie within the field of application of the predicate “triangular.” Therefore it cannot be triangular — nor, for that matter, “not triangular.” The same applies in our case: the doorpost is neither obligated nor exempt with respect to tzitzit. It simply does not belong here.

Take another example, somewhat different: “The present king of France is bald.” Let us now go out and examine whether this statement is true or false. We can inspect the set of bald people and not find the present king of France there. Yet, surprisingly, even if we inspect the set of people with hair, we will still not find the present king of France there. How can this be? Have the laws of logic broken down? The answer is simple: present-day France has no king. So too here: in the world of those obligated in tzitzit we do not find the doorpost, and neither do we find it in the world of those exempt from tzitzit. The doorpost does not exist within the domain of application of the commandment of tzitzit.

The second problem with a kal va-homer based on two data points is that we may have two domains that are effectively transparent to one another. Entry may simply not belong to the domain of obligation or exemption with respect to blessing, and exit may simply not belong to the domain of obligation or exemption with respect to washing. In such a situation we cannot perform a kal va-homer, because we have no axis of comparison. We cannot fill in the empty cells — not because we do not know what to fill them with, for there are two opposite directions in which to fill them, as we saw in the first problem, but because the law is not relevant to them at all.¹

In the absence of an axis of relation, there is also no place for comparison and no basis for saying that entry is more stringent than exit because entry requires washing whereas exit does not. Exit is not exempt from washing; rather, it simply does not fall under either exemption or obligation in this regard.

A Two-Data-Point Kal va-Homer Without the Second Problem

And yet this is not always the case. Sometimes the empty cells are merely the result of uncertainty, not of irrelevance. In the case of the doorpost and tzitzit, irrelevance seems plausible. But in our case, regarding entry and exit, the parameters are clearly relevant; the problem is only lack of knowledge. Indeed, the midrash itself eventually concludes in one direction, thereby turning the discussion into an ordinary hermeneutical kal va-homer with three data points.

This can be seen from the very formulation of the midrash. When the problem is irrelevance, there is no point in formulating both directions — the “reversal” — and wavering between them. In a case of irrelevance we are not in doubt as to which direction is correct; rather, we know with certainty that neither is valid.

Two Ways to Complete Missing Information

In a situation where we have only two data points because of lack of information, and not because of irrelevance, we have seen that there is room to try to complete the missing information by filling the empty cells in the table. This can be done in two ways:

1. Find the third datum and complete the table.
2. Decide between the two possible directions by conceptual reasoning.

This is what our midrash chooses to do: since entry from the profane into the holy requires blessing or washing more than exit from the holy into the profane, it is clear that the first kal va-homer is the correct one. We have no source that entry requires a blessing. The reasoning rests on the fact that the alternative is less plausible.

But why assume from the outset that one direction is preferable? One might equally have said that this is a case of irrelevance, in which no decision between the two directions is possible. Clearly, our midrash knows in advance that the problem here is lack of information rather than irrelevance; otherwise the argument would not be valid.

Here we see the dimension of reasoning that exists within kal va-homer. Before performing the exposition, the interpreter must decide, on the basis of reason alone, whether the parameters are relevant to one another.

Can There Be Irrelevance in a Case of Three Data Points?

When the third datum is actually found, it then becomes clear that the situation involved only lack of information and not irrelevance. For example, if we were to find an explicit source exempting a doorpost from tzitzit, it would become clear that there too the problem was lack of information and not irrelevance.

Finding the missing information essentially returns us to the ordinary hermeneutical kal va-homer based on three data points. In such a situation there is usually full relevance among the variables, and one may perform the kal va-homer. A case of a three-data-point hermeneutical kal va-homer that expresses not ignorance but irrelevance — and therefore cannot sustain a kal va-homer — is rare, but it is possible.

For example, suppose exit is altogether irrelevant to the question of washing, but entry is relevant to the matter of blessing. In such a case, even if the third law is known — namely, that entry requires a blessing — one still cannot perform a kal va-homer and infer that exit does not require washing.

How, then, will we know whether we are dealing with irrelevance or with lack of information? As stated, we can know this only by reasoning. Notice that so long as we have not determined the character of the absences in the table — whether they reflect irrelevance or lack of information — we cannot perform a kal va-homer. The conclusion is that every ordinary hermeneutical kal va-homer rests on an a priori act of reasoning by the interpreter. It is not mere technical formalism, but the product of an analysis of conceptual relevance.

Summary: Two Kinds of Absence in the Table of a Kal va-Homer

It is therefore crucial to distinguish between a case in which the absence of a datum results from irrelevance and one in which the absence results from lack of knowledge. In the second case, if there are two data points, one may try to complete the missing information — that is, the third datum — and in the end perform the kal va-homer on the basis of the new datum. And if there are already three data points, one may perform a kal va-homer on their basis. But when the absence of the datum stems from irrelevance, there is no point at all in searching for the missing datum, nor in performing a kal va-homer, whether there are two data points or three.

In fact, in such a case the table is fully complete. In the empty cells of such a table there are markings that are neither “+” nor “-,” but rather “irrelevant.”

B. If There Is No Flour, There Is No Torah: Blessing Before and After

Another Example of a Two-Data-Point Kal va-Homer: Babylonian Talmud, Berakhot 21a

There are several isolated examples in the Talmud of kal va-homer expositions based on only two data points. One of the best known and clearest is found in the sugya of the Babylonian Talmud, Berakhot 21a. The sugya there is formulated in a systematic and lucid manner, and its assumptions are explicit in the text itself. We therefore choose to focus specifically on it. This is the language of the Gemara:

Rav Yehudah said: From where do we know that grace after meals is commanded by the Torah? As it is said: “You shall eat and be satisfied and bless.” From where do we know that the blessing over Torah before it is commanded by the Torah? As it is said: “When I proclaim the name of the Lord, ascribe greatness to our God.” Rabbi Yohanan said: We learn the blessing over Torah after it from grace after meals by kal va-homer, and grace before meals from the blessing over Torah by kal va-homer. The blessing over Torah after it from grace after meals by kal va-homer: if food, which does not require a blessing before it, does require a blessing after it, then Torah, which does require a blessing before it, is it not all the more so that it requires a blessing after it? And grace before meals from the blessing over Torah by kal va-homer: if Torah, which does not require a blessing after it, does require a blessing before it, then food, which does require a blessing after it, is it not all the more so that it should require a blessing before it? But this can be refuted: what is unique about food is that one derives benefit from it, and what is unique about Torah is that it is eternal life. Moreover, we learned in a mishnah: over food one blesses after it, but one does not bless before it. This is a refutation.

— Babylonian Talmud, Berakhot 21a

The Gemara opens by noting that two data points are known to us, and they are explicit in the verses:

1. One must bless after food — grace after meals.²
2. One must bless over Torah before it — the blessing over Torah.³

The two other data points are not found in Scripture. We therefore have a two-data-point structure of the following sort:

Action/state	Before	After
Food (flour)		+
Torah	+

The other two cells are unknown. We must now ask what kind of lack this is. Is it irrelevance, or merely absence of information? The practical consequence is that if it is irrelevance, there is no point in beginning a kal va-homer in either direction. But if it is lack of information, then it can be completed in one of the two ways we saw at the end of section A.

By straightforward reasoning, there seems to be relevance between blessings before and after, both with respect to Torah and with respect to food.⁴ If so, it is fairly clear that this is a case in which one may attempt a kal va-homer on the basis of two data points. That is indeed the next move of the sugya.

Rabbi Yohanan’s Two A Fortiori Inferences

Rabbi Yohanan proposes, in the first direction, to learn the blessing over Torah after it from grace after meals by kal va-homer. After that inference, the table looks like this:

Action/state	Before	After
Food (flour)	– (filled in by assumption)	+
Torah	+	+ (result of the kal va-homer)

Notice that at the base of this kal va-homer lies the assumption — which Rabbi Yohanan states explicitly — that food does not require a blessing before it.

And in that very same statement Rabbi Yohanan also proposes the opposite kal va-homer: to learn grace before meals from the blessing over Torah. After that inference, the table looks like this:

Action/state	Before	After
Food (flour)	+ (result of the kal va-homer)	+
Torah	+	– (filled in by assumption)

Notice that at the base of this kal va-homer lies the assumption — and Rabbi Yohanan states this explicitly as well — that Torah does not require a blessing after it.

But, as we have already noted, these two kal va-homer arguments contradict one another. According to the conclusion of the first kal va-homer, Torah does require a blessing after it. That removes the basis of the second kal va-homer, since its hidden assumption is the opposite. And the reverse is equally true.

From the course of the Gemara, this point does not seem to trouble it at all. It is prepared to entertain both kal va-homer arguments together. The problems the sugya raises are refutations of each kal va-homer separately. This is indeed how Rashi explains the passage:

“This can be refuted” — in both directions. When you come to learn Torah from food, one may object: what is unique about food is that one derives benefit from it. And when you come to learn food from Torah, one may object: what is unique about Torah is that it is the life of the world to come.

— Rashi on Babylonian Talmud, Berakhot 21a

How can this be? How can Rabbi Yohanan adopt such a double kal va-homer on the basis of two data points, when there is an open contradiction here? Seemingly, each direction refutes the other.

First Proposed Solution: Rashi’s Remark

From Rashi’s words on the sugya, it appears that he sensed this difficulty, and therefore he interprets Rabbi Yohanan’s language somewhat differently from its plain sense:

“Does not require beforehand” — that is to say, we have not found an explicit verse requiring a blessing beforehand. “Requires afterward” — as it is written, “You shall eat and be satisfied and bless.” “Torah, which requires beforehand” — as we have stated.

— Rashi on Babylonian Talmud, Berakhot 21a

In other words, Rashi grounds the relative leniency of food as compared to Torah in the fact that we do not find an explicit verse obligating a blessing over food beforehand, not in the fact that food is actually exempt from a blessing. If so, according to Rashi’s proposal, the marking in the cells filled in by working assumption does not have the same status as the cells filled in by actual data. The sign “-” no longer denotes exemption but the absence of an obligating verse. The assumption is that even if, in actual halakha, food does require a blessing before it, the fact that there is no explicit verse to that effect still counts as a leniency.⁵

Rashi’s proposal certainly eases the difficulty, but it does not solve it. In the page on Parashat Noah we explained in detail how kal va-homer operates. The general scheme is this: one takes two of the data points and constructs from them a generalization. One then uses that generalization together with the third datum in order to derive the conclusion.

Let us demonstrate this in our case. Take two data points: food does not require a blessing before it, while Torah does. Now generalize: Torah is more stringent than food in every respect. Next take the third datum: food requires a blessing after it. Finally derive from it, by means of the generalization: if food, the less stringent case, requires a blessing after it, then Torah, the more stringent case, surely does as well.

Thus every kal va-homer rests on a generalization. In Rabbi Yohanan’s first kal va-homer, even according to Rashi’s formulation, which changes only the basis of the generalization but still accepts the generalization itself, the underlying generalization is that Torah is more stringent than food. In Rabbi Yohanan’s second kal va-homer, by contrast — and here too the point remains true even according to Rashi — the underlying generalization is that food is more stringent than Torah. But these two generalizations contradict one another, even after Rashi’s remark. How, then, can both directions of the kal va-homer be adopted simultaneously?

Second Proposed Solution

In light of the difficulty, perhaps we may interpret the refutations raised by the Gemara itself as indicators. That is, the Gemara may indeed mean to reject Rabbi Yohanan’s two kal va-homer arguments by allowing each one to be displaced by the other. The rejection of the first kal va-homer comes by force of the second, and vice versa. But a rejection based on some law should always point to a stringency rooted in reasoning. For example, the rejection that with Torah there is no explicit command to bless afterward indicates that Torah is less stringent than food. We may then ask: why, in fact, is it less stringent? This is what the Gemara explains when it says that Torah is eternal life — though its purpose there is to refute the kal va-homer.

The problem is that on this reading it is not clear why the Gemara assumes that both kal va-homer arguments are refutable. Seemingly, it should have sufficed to refute one of them and leave the other standing. From here it is clear that these lines of reasoning do not arise merely from the absence of the relevant laws from the Torah; rather, they are present a priori in the mind of the sage who offers the refutation.⁶

C. Kal va-Homer as a Textual Hermeneutic Principle: A Third Explanation

Reformulating the Difficulty Regarding Every Kal va-Homer

In fact, the difficulty boils down to this: the table as it appears after Rabbi Yohanan’s two kal va-homer arguments is not internally consistent. Rabbi Yohanan’s table is the following:

Action/state	Before	After
Food (flour)	-/+	+
Torah	+	-/+

Here “-/+” indicates that the law exists in principle, but with a weaker degree of force.

We can now immediately see that the datum regarding food before it does not allow the kal va-homer from which the conclusion regarding Torah after it is derived, at least in the formulation presented above. The reason is that when we wish to derive the blessing over Torah after it by kal va-homer, the inference rests on the generalization that Torah is more stringent than food. But according to the conclusion, Torah is actually less stringent than food, since the obligation to bless afterward in the case of Torah is weaker, marked “-/+,” than the obligation to bless after food, marked “+.”

But a little reflection shows that such a problem arises in every kal va-homer. We have seen in the past that a law derived by kal va-homer has weaker force than a law stated explicitly in the Torah. At least according to Maimonides — see the pages on Parashat Hayyei Sarah, part II, Yitro, Mishpatim, and others — this is why punishments are not imposed on the basis of inference. Yet specifically in the case of kal va-homer this is puzzling. Unlike the other hermeneutical principles, kal va-homer is based on the assumption — that is, the generalization — that the derived case is more stringent than the source case. But the source case is a law that appears explicitly in Scripture, whereas the derived case is a law generated by the kal va-homer itself, that is, by exposition, and is therefore weaker. If so, the conclusion of the kal va-homer contradicts its premises.⁷ Put differently: the result of the kal va-homer becomes a refutation of the inference itself — what can be said for the derived case, whose legal force is weaker, because it emerges only from exposition, than the source case, which is written explicitly in Scripture?

Third Proposed Solution: Kal va-Homer as a Textual Principle

It seems that in order to answer this we must distinguish between two different stages in the exposition. When we examine the data within Scripture itself, a picture emerges in which the derived case is more stringent than the source case. According to the conclusion, however, the result is a weaker obligation than that of the source case.

Therefore, kal va-homer should be understood as a textual hermeneutic principle, not as a logical one. When we examine Scripture alone, it emerges that the derived case is more stringent than the source case. To be sure, this is not their true relation, because once the kal va-homer is completed the opposite relation will also be created. Still, that is the picture reflected by Scripture as such. Such a scriptural picture instructs us to derive the one from the other by means of kal va-homer. Once we have derived the new law, a situation is created in which the true relation between the halakhot is exposed: the source case, which is explicit in the Torah, is more stringent than the derived case, which is known only through exposition. But for the purpose of kal va-homer, what determines matters is only the reflection of their relation within Scripture. It seems that there is no escape from saying that the principle of kal va-homer is textual and not logical. Or, in other words: the leniency and stringency used by kal va-homer are not the true halakhic leniency and stringency, but only those that emerge from the scriptural picture.

Let us sharpen the point by means of a visual metaphor. According to our proposal, kal va-homer must be performed in two stages. In stage one we gather the relevant scriptural data and enter them in a table on transparency A. In stage two we perform the inference of kal va-homer on the basis of the scriptural data. From that hermeneutic inference new halakhot emerge. Those halakhot emerge from the exposition, and therefore do not appear in Scripture itself. We therefore record them on a second transparency, placed over the first. The full halakhic picture is the combination produced by the two transparencies: the scriptural and the exegetical. But refutations of a kal va-homer, and the data used for the kal va-homer itself, cannot belong to the world of the second transparency; they can belong only to the first. The data on the second transparency are valid in halakha, but they are not scriptural.

To summarize, kal va-homer is also a tool for interpreting Scripture, not only a logical inference. For that reason one cannot refute a kal va-homer by saying: what can be said of the derived case, whose law is created by exposition? That refutation belongs to the second transparency.

If what we have said is correct, then the problem created by Rabbi Yohanan’s double kal va-homer disappears as well. There too, only the true halakhic relation is contradictory, whereas for the purpose of kal va-homer what matters is specifically the scriptural relation, not the true halakhic one. And from the standpoint of Scripture, the laws of blessing after Torah and blessing before food are simply absent.

If so, Rashi’s proposal in the sugya of Berakhot is not something unique to Rabbi Yohanan’s kal va-homer alone. According to our approach, in every kal va-homer the leniency and stringency are determined by the written text and not by the law itself. It thus turns out that Rashi’s proposal in the sugya of Berakhot really does solve all the difficulties, contrary to what a superficial glance might suggest.

Implications and Sources for Our Proposal

According to our approach, namely that kal va-homer is not merely a logical consideration but also a textual hermeneutic tool, it becomes clear why the Torah transmits the principle of kal va-homer as part of the entire system of hermeneutical principles.⁸

According to our approach, it is also very easy to understand the tannaitic view that one does not perform a kal va-homer from a halakha le-Moshe mi-Sinai — see Mishnah Nazir 56b, and this is also the accepted halakha.⁹ Since a halakha le-Moshe mi-Sinai is not written in the Torah, Rabbi Eliezer, in the mishnah there, holds that kal va-homer cannot be applied to it, because kal va-homer is not a logical rule at all but an interpretive rule whose force extends only to what is found in Scripture. Likewise, it is explained in several places that one also does not refute a kal va-homer on the basis of a halakha le-Moshe mi-Sinai.¹⁰ This seems to be strong evidence for our position here.

In conclusion, let us note a fascinating source proving that kal va-homer is an interpretive rather than a logical principle. See Hiddushei ha-Rashba on Babylonian Talmud, Bava Kamma 2b, s.v. “aval be-mehubberet,” and the explanation in Birkat Shemuel, by Rabbi Barukh Ber Leibowitz, Bava Kamma, sec. 2; but this is not the place to elaborate.¹¹

Footnotes