Sukkah 12A

אי: מה חגיגה בעלי חיים, אף סוכה נמי בעלי חיים!

The Talmud asks: If that juxtaposition is the source of the halakha, say: Just as the Festival peace-offering is brought from animals, so too the sukka roofing should consist of animals. As that is clearly not the case, that verse cannot be the source for the roofing of the sukka.

כי אתא רבין אמר רבי יוחנן, אמר קרא: ״באספך מגרנך ומיקבך״, בפסולת גורן ויקב הכתוב מדבר.

The Talmud cites a different source: When Ravin came from Eretz Yisrael to Babylonia he said that R' Yoḥanan said that the verse states: “You should prepare for you the festival of Sukkot for 7 days as you gather from your threshing floor and from your winepress” (Deuteronomy 16:13), and the rabbis interpreted that it is with regard to the waste of the threshing floor and of the winepress that the verse is speaking. One uses grain stalks and vines for roofing the sukka, materials that are not susceptible to ritual impurity and grow from the ground.

ואימא גורן עצמו ויקב עצמו! אמר רבי זירא: ״יקב״ כתיב כאן, ואי אפשר לסכך בו.

The Talmud asks: And say that the verse teaches that one uses the items placed on the threshing floor itself, i.e., stalks with the grain still attached to them, and the items placed in the winepress itself, i.e., vines with the grapes still attached, as roofing. Grain and grapes, like all foods, are susceptible to ritual impurity. If the verse is interpreted in this manner, the Mishnah’s criteria for roofing fit for a sukka could not be derived from it. R' Zeira said: “Winepress” is written in the verse here, referring to the wine, and it is impossible to roof with wine. Apparently, the verse is referring to stalks and sheaves but not to produce.