Q&A: The Binding Force of Customs
The Binding Force of Customs
Question
Hello Rabbi,
Could you clarify what the source of the binding force of customs is? The Talmud in Nedarim 15 and 81 brings that there is a rabbinic-level prohibition of “he shall not break his word,” and from other sources the verse “Do not forsake the teaching of your mother” is cited. (Maimonides speaks about “do not turn aside” with respect to customs that received the approval of a religious court, but that is not the kind of custom I am discussing.) The Geonim added another support from the verse “Do not move a boundary marker…” On the face of it, it is not entirely clear what force customs really have—what is the force of a rule that comes out of a verse in Proverbs? I have seen later authorities who suggested that there is something here connected to God’s will or the acceptance of the nation (similar to suggestions given for the question why we must listen to the Sages according to Nachmanides; this seems to emerge from Kovetz Shiurim, Kiddushin 24:14, and Rabbi Kook in Da’at Kohen 84 and Adar HaYakar 4). But I would be happy to understand more precisely what the force is and what generates these obligations.
I thought perhaps to suggest an approach, and I would be glad to hear your opinion on it. You are accustomed to distinguishing between two kinds of authority—formal and substantive. Would it be correct to formulate it this way: the reason we become obligated by customs is because of a consideration of substantive authority—that is, apparently my ancestors who practiced such-and-such a custom probably had good reasons for it, and therefore it makes sense that I should feel bound by it (like listening to a doctor because of his knowledge and experience). Because seemingly it is hard to find a basis for customs in formal authority (obviously with respect to customs that were not ratified by a religious court that has formal authority). (If customs are in fact based on substantive authority, then seemingly they are binding only so long as I accept the logic behind the custom. According to this, when in the Talmud Rabbi Yohanan says to the people of Beishan (in Pesachim chapter 4) to follow the practice of their ancestors with respect to travel on Sabbath eve, on the basis of “Do not forsake the teaching of your mother,” is that essentially saying: trust that your parents knew what they were doing—but in essence, if they wanted, they could have refused and not listened?)
Thank you very much,
Michael Israel
Answer
I haven’t studied the topic in depth, so I can’t give a well-founded answer. In general, it is fairly clear that all these sources are after-the-fact supports. They teach that there is value in preserving a custom. But that does not turn it into a halakhic prohibition, because otherwise it stops being a custom and becomes a prohibition. So it doesn’t really matter from which verse you derive it.
By the way, “Do not forsake” appears in the Talmud in Pesachim regarding ancestral custom, and it does not seem to have received the agreement of a religious court.
Discussion on Answer
I answered that within my remarks above. These are not real sources in the usual halakhic sense of the word. Just as “do not turn aside” does not make every rabbinic prohibition into a Torah prohibition. Because it is not really a source.
To the writer of the question, hello, I would be happy to speak with you about the topic of the question. It seems you have studied the topic, and I personally am looking for sources related to it. I am looking for sources that say that a post-Talmudic custom that has no Talmudic root is not binding. So far I have found only one source, and even that is uncertain, namely Maimonides. Here is a question I asked a rabbi in the past on this subject:
https://net-sah.org/faq/49398
My email, if you are willing to talk: ecoalper@gmail.com
The reason I am looking for sources for the claim that a post-Talmudic custom is not binding is the current situation today of a very heavy halakhic burden that has turned from custom into an actual obligation, and to me it feels like this does not contribute to the Jewish people
The writer added:
Hello Rabbi,
Sorry, I sent a question a few minutes ago, and I just wanted to add one more aspect to the question—if we assume that there is really a kind of reasoning that obligates preserving customs (by virtue of substantive authority), then does that make it something like Torah-level law because of “why would I need a verse if logic is enough”? Put differently: when does a general logical argument create a Torah-level law, and when is logic just a correct or fitting idea but does not generate something binding (certainly not Torah-level)?
Thank you very much,
Michael Israel