Leviticus 23:40-43

And ye shall take you on the first day the fruit of goodly trees, branches of palm-trees, and boughs of thick trees, and willows of the brook; and ye shall rejoice before Jehovah your God seven days. And ye shall keep it a feast unto Jehovah seven days in the year: it is a statute for ever throughout your generations; ye shall keep it in the seventh month. Ye shall dwell in booths seven days; all that are home-born in Israel shall dwell in booths; that your generations may know that I made the children of Israel to dwell in booths, when I brought them out of the land of Egypt: I am Jehovah your God.