Sukkah 2a
סוכה ב׳ א — ד"ה אָמַר רַבָּה
Sukkah 2a:8
The opening discussion of tractate Sukkah explains the legal meaning of dwelling in a sukkah, including the requirement that the sukkah’s covering provide shade. This is the principal Talmudic locus for the sukkah’s physical covering and visibility of the sky.
אָמַר רַבָּה, דְּאָמַר קְרָא: ״לְמַעַן יֵדְעוּ דוֹרוֹתֵיכֶם כִּי בַסּוּכּוֹת הוֹשַׁבְתִּי אֶת בְּנֵי יִשְׂרָאֵל״, עַד עֶשְׂרִים אַמָּה, אָדָם יוֹדֵעַ שֶׁהוּא דָּר בַּסּוּכָּה, לְמַעְלָה מֵעֶשְׂרִים אַמָּה — אֵין אָדָם יוֹדֵעַ שֶׁדָּר בַּסּוּכָּה, מִשּׁוּם דְּלָא שָׁלְטָא בַּהּ עֵינָא. רַבִּי זֵירָא אָמַר מֵהָכָא: ״וְסוּכָּה תִּהְיֶה לְצֵל יוֹמָם מֵחוֹרֶב״, עַד עֶשְׂרִים אַמָּה אָדָם יוֹשֵׁב בְּצֵל סוּכָּה, לְמַעְלָה מֵעֶשְׂרִים אַמָּה — אֵין אָדָם יוֹשֵׁב בְּצֵל סוּכָּה אֶלָּא בְּצֵל דְּפָנוֹת.
Rabba said that it is derived as the verse states: “So that your future generations will know that I caused the children of Israel to reside in sukkot when I took them out of the land of Egypt” (Leviticus 23:43). In a sukka up to twenty cubits high, even without a concerted effort, a person is aware that he is residing in a sukka. His eye catches sight of the roofing, evoking the sukka and its associated mitzvot. However, in a sukka that is more than twenty cubits high, a person is not aware that he is residing in a sukka because his eye does not involuntarily catch sight of the roof, as at that height, without a concerted effort one would not notice the roofing. Rabbi Zeira said that it is derived from here: The verse states: “And there shall be a sukka for shade in the daytime from the heat, and for refuge and cover from storm and from rain” (Isaiah 4:6). In a sukka up to twenty cubits high, a person is sitting in the shade of the sukka, i.e., the shade of the roofing; in a sukka that is more than twenty cubits high, a person is not sitting in the shade of the roofing of the sukka but rather in the shade of the walls of the sukka, as their considerable height provides constant shade, rendering the shade of the roofing irrelevant.


