Study Niddah folio 23A with parallel Hebrew-English text, traditional commentary, and modern study tools. Free access to Babylonian Talmud online.
and derive the halakha from the analogy that is free on both sides. And it is for this reason that God rendered the verbal analogy between animal and man free on both sides, so that one would not derive the halakha from the verbal analogy between sea monster and man, which is free on only one side.
Rav Aḥa, son of Rava, teaches in the name of R' Elazar a more lenient version of the aforementioned principle of exegesis of verbal analogy: With regard to any verbal analogy that is not free at all, one can derive halakhot from it, but one can also refute it logically. If the verbal analogy is free
The Talmud asks: But if so, according to the Rabbis, what difference is there between a verbal analogy that is free on one side and one that is not free at all? In both cases, the Rabbis hold that one can derive halakhot from such a verbal analogy but one can also refute it.
The Talmud answers: The difference is in a case where you find two mutually exclusive verbal analogies, one that is free on one side and one that is not free at all, and neither does this one have a logical refutation nor does that one have a logical refutation. In such a case, we disregard the ana
The Talmud asks: And here, with regard to the verbal analogy between man and sea monster, which was rejected because it is free on only one side, what logical refutation is there on account of which this verbal analogy is rejected? The Talmud answers: The verbal analogy between man and sea monster