Leviticus 23:40-42

40On the first day you are to gather the fruit of majestic trees, the branches of palm trees, and the boughs of leafy trees and of willows1 of the brook. And you are to rejoice before the LORD your God for seven days. 41You are to celebrate this as a feast to the LORD for seven days each year. This is a permanent statute for the generations to come; you are to celebrate it in the seventh month.

42You are to dwell in booths2 for seven days. All the native-born of Israel must dwell in booths,