Leviticus 23:40-43

40 And you shall take for yourselves on the first day the fruit of beautiful trees, branches of palm trees, the boughs of leafy trees, and willows of the brook; and you shall rejoice before the Lord your God for seven days. 

41 You shall keep it as a feast to the Lord for seven days in the year. 

It shall be a statute forever in your generations. You shall celebrate it in the seventh month. 

42 You shall dwell in booths for seven days. All who are native Israelites shall dwell in booths, 43 that your generations may know that I made the children of Israel dwell in booths when I brought them out of the land of Egypt: I am the Lord your God.’”