Lev 23:39-43

39Now, the fifteenth day of the seventh month, when you have gathered in the produce of the land, you shall keep the festival of the Lord, lasting seven days; a complete rest on the first day, and a complete rest on the eighth day.40On the first day you shall take the fruit of majestic trees, branches of palm trees, boughs of leafy trees, and willows of the brook; and you shall rejoice before the Lord your God for seven days.41You shall keep it as a festival to the Lord seven days in the year; you shall keep it in the seventh month as a statute forever throughout your generations.42You shall live in booths for seven days; all that are citizens in Israel shall live in booths,43so that your generations may know that I made the people of Israel live in booths when I brought them out of the land of Egypt: I am the Lord your God.