Leviticus 23:40-43

40And ye shall take on the first day the fruit of beautiful trees, palm branches and the boughs of leafy trees, and willows of the brook; and ye shall rejoice before Jehovah your 1God seven days.

41And ye shall celebrate it as a feast to Jehovah seven days in the year: [it is] an everlasting statute throughout your generations; in the seventh month shall ye celebrate it.

42In booths shall ye dwell seven days; all born in Israel shall dwell in booths;

43that your generations may know that I caused the children of Israel to dwell in booths, when I brought them out of the land of Egypt: I am Jehovah your 2God.