daf bit: (prompted by) Zevachim 50

[cellio]

Today's daf has a long discussion of how some of the rules of talmudic reasoning relate to each other, drawing examples from the laws concerning the temple service. In lieu of that discussion (which does not fit in the margins of this daf bit), I offer a summary of the rules cited on this daf:

• Kal v'chomer: I learned this as the "how much the moreso" argument, but it literally means "simple and complex" "lenient and strict" (thanks for the correction). This is the argument that says that if such-and-such (simple, minor) behavior is a problem, then surely thus-and-such amplified version of it is. I understand that there is support for running the logic in the other direction too, though I don't know how that works.
• Gezeirah shavah: this is an analogy drawn between two uses of the same word in torah. If the word means such-and-such when used here, then it must mean such-and-such when used over here too, and you can use this reasoning to clarify ambiguous interpretations. I am told that originally this rule applied only in cases where a word appears exactly two times, but that doesn't seem to be the case any more.
• Hekkesh: this is an analogy based on facts rather than words, and is sometimes described as being related to the gezeirah shavah. If I understand correctly, this is the rule that's in play when you see reasoning like "if we do such-and-such for a sin offering, then we must do the same thing for a wholeness offering".

The daf also refers to binyan av, which has something to do with a passage serving as a standard for interpreting others, but I lack good examples or a clearer understanding. (There are more rules too; these are just the ones discussed here.)

Comments

[zevabe.livejournal.com]

The "backwards" kal v'chomer: Since thus is permitted in a strict case, surely it is permitted in a lenient case.

Example: Since x is permitted on Shabbat, it is permitted on Yom Tov as well (yom tov being more lenient than Shabbat, due to permissions for food).

Gezeira Shavah: Some of them connect really odd words. A famous example: Regarding Pesach it says 15th. Regarding Sukkot it says 15th. Therefore, just as you must eat [matzah] on the first night of Pesach even if you don't want to, on the first night of Sukkot you must eat bread in the sukkah even if you don't want to.

Binyan Av: I ad to look in Artscroll siddur to find an example, but its not bad. In regard to forbidden relations the Torah speaks of a half-sister. This creates a binyan av that for other prohibited sistery relationships (e.g. father's sister, wife's sister, etc) the half-sister counts and is thus prohibited.

[cellio]

Thanks for the information! (And I didn't know that about Sukkot.)