What is the essential nature of a Sukkah?

This is the principle with regard to the roofing of a sukka: One may not roof the sukka with anything that is susceptible to ritual impurity or whose growth is not from the ground. From where are these matters with regard to the roofing of a sukka derived? Reish Lakish said that the verse states: “And there went up a mist from the earth, and watered the entire face of the ground” (Genesis 2:6); just as mist, i.e., a cloud, is a substance not capable of contracting ritual impurity, and its growth is (it arises) from the ground, so too, the roofing of the sukka must consist of a substance that is not susceptible to ritual impurity and its growth is from the ground. Since the mitzvah of sukkah evokes the clouds of glory with which God enveloped the Israelites in the desert, the roofing should be like that of a cloud.

This works out well according to the one who said that the sukkot mentioned in the verse: “I made the children of Israel reside in sukkot” (Leviticus 23:43), were clouds of glory, as it is reasonable that the roofing of the sukka is modeled after clouds. However, according to the one who said that the children of Israel established for themselves actual sukkot in the desert, and the sukkot of today commemorate those, what can be said? According to that opinion, there is no connection between a sukka and a cloud. As it is taught: “I made the children of Israel reside in sukkot”; these booths were clouds of glory, this is the statement of Rabbi Eliezer. Rabbi Akiva says: They established for themselves actual sukkot. This works out well according to Rabbi Eliezer; however, according to Rabbi Akiva what can be said?

When Rav Dimi came from Eretz Yisrael to Babylonia, he said that Rabbi Yoḥanan said that the verse states: “You shall prepare for you the festival of Sukkot” (Deuteronomy 16:13). The expression “festival of Sukkot” likens sukka to the Festival peace-offering [ḥagiga]. Just as the Festival peace-offering is an item not susceptible to ritual impurity, and its growth is from the ground, as animals draw nourishment from vegetation, so too, the roofing of the sukka must be a substance that is not susceptible to ritual impurity and its growth is from the ground.

When Ravin came from Eretz Yisrael to Babylonia he said that Rabbi Yoḥanan said that the verse states: “You shall prepare for you the festival of Sukkot for seven days as you gather from your threshing floor and from your winepress” (Deuteronomy 16:13), and the Sages 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.