Study Sukkah folio 18B with parallel Hebrew-English text, traditional commentary, and modern study tools. Free access to Babylonian Talmud online.
as we say that the edge of the roof descends and seals the opening. The edge of the roof itself is considered as though it were a small partition that extends downward and forms a wall. Rava said: This sukka is unfit, as we do not say that the edge of the roof descends and seals.
Rava said to Abaye: According to you, who said: The edge of the roof descends and seals the opening like a wall, then in a case where the roofing of the sukka consists of straight beams, even if one removed the middle wall, leaving the sukka with only two parallel walls, the sukka would nevertheles
The Talmud suggests: Let us say that Abaye and Rava disagree with regard to the same issue that was the subject in the dispute of Rav and Shmuel; they are merely elaborating on a fundamental dispute between other amora’im. As it was stated: Amora’im disagree with regard to a portico, which has a
The Talmud rejects this comparison and says: According to the opinion of Shmuel, everyone, even Abaye, agrees that one does not apply the principle: The edge of the roof descends and seals, to the case of a sukka.