Sukkot סוכות
Seven days in a booth with the four species — the festival of harvest and of memory of the desert.
Sukkot begins five days after Yom Kippur and changes the key entirely: from judgment to a joy the Torah states outright — «you shall be only joyful». For seven days one eats, and many sleep, in a sukkah, a temporary booth roofed with cut plants through which the stars must be visible.
The Torah explains: «so that your generations will know that I settled the children of Israel in booths». Rabbi Akiva took this literally, Rabbi Eliezer as the clouds of glory around the camp; both readings live side by side.
The second commandment is the four species, taken together. Midrash likens them to four kinds of people — and says they are bound into one bundle.
In the Temple the water libation was accompanied by the Simchat Beit haShoeva, of which it was said: whoever has not seen it has never seen joy.