Leviticus 23:39-40

23:39 “‘On the fifteenth day of the seventh month, when you gather in the produce of the land, you must celebrate a pilgrim festival of the Lord for seven days. On the first day is a complete rest and on the eighth day is complete rest. 23:40 On the first day you must take for yourselves branches from majestic trees – palm branches, branches of leafy trees, and willows of the brook – and you must rejoice before the Lord your God for seven days.