סוכה ד׳Sukkah 4

Mishnah 1א׳

לוּלָב וַעֲרָבָה, שִׁשָּׁה וְשִׁבְעָה. הַהַלֵּל וְהַשִּׂמְחָה, שְׁמֹנָה. סֻכָּה וְנִסּוּךְ הַמַּיִם, שִׁבְעָה. וְהֶחָלִיל, חֲמִשָּׁה וְשִׁשָּׁה:

Lulav [the taking of the lulav] and aravah [for the circling of the altar] — (sometimes the mitzvah is) six (days) and (sometimes) seven. [Sometimes it overrides the Sabbath and is seven days; and sometimes it does not override the Sabbath and is six (to be explained later)]. Hallel and rejoicing are eight. [(Hallel:) to complete the Hallel all eight days (as opposed to Pesach), for the days of the festival (of Succoth) are distinct in their offerings. (rejoicing:) to eat the flesh of peace-offerings at the time of the Temple, it being written (Deuteronomy 16:14): "And you shall rejoice in your festival," and there is no rejoicing at the time of the Temple except with peace-offerings, viz. (Ibid. 27:7): "and you shall slaughter peace-offerings, and you shall eat them there, and you shall rejoice."] Succah [sitting in the succah] and the water libation [at the morning temidim of the festival] — seven. And the chalil (the flute), five and six. [At the simchath Beth Hashoeva, they rejoiced in the festival in honor of the drawing of the water for the libations, and they would play on flutes and viols. And that chalil overrides neither Sabbath nor festival.]

Mishnah 2ב׳

לוּלָב שִׁבְעָה כֵּיצַד, יוֹם טוֹב הָרִאשׁוֹן שֶׁל חָג שֶׁחָל לִהְיוֹת בְּשַׁבָּת, לוּלָב שִׁבְעָה, וּשְׁאָר כָּל הַיָּמִים, שִׁשָּׁה:

Lulav — seven. How so? If the first day of the festival fell out on Shabbath, lulav — seven. [For the first day (of the festival) overrides Shabbath, it having a basis in the Torah (for taking the lulav even) in the borders (i.e., outside of the Temple), viz. (Leviticus 23:40): "And you shall take for yourselves on the first day"]. All the other days, six. [If the first day of the festival falls out on any of the weekdays, so that Shabbath falls out on Chol Hamoed, it does not override. And even though all seven days obtain in the Temple by Torah law, the sages established their decree (against taking the lulav) for the other days of the festival, since they have no Torah basis (for taking the lulav) in the borders (on those days). And, in truth, even today the taking of the lulav should override Shabbath on the first day of the festival; but because we are not expert in the fixing of the New Moon, so that it (that day) may not be the first day of the festival, we do not override the Sabbath on the basis of a possibility. And in taking it, there is no (Torah proscribed) Sabbath labor, but merely the moving of it. (Still, it is forbidden) lest he take it in his hand and go to an expert to learn the blessing or the order of the shakings (na'anuim) and come to carry it four cubits in the public domain. And this is also the reason that we do not blow the shofar or read the Megillah (on Shabbath)].