Leviticus 23:34, 40

“Say to the children of Israel, ‘On the fifteenth day of this seventh month, and for seven days, is the Feast of Booths (Tabernacles) to the LORD.

Now on the first day you shall take for yourselves the foliage of beautiful trees, branches of palm trees, and boughs of thick (leafy) trees, and willows of the brook [and make booths of them]; and you shall rejoice before the LORD your God for seven days.