Leviticus 23:39-41

‘Also on the fifteenth day of the seventh month, when you have gathered in the fruit of the land, you shall keep the feast of the LORD for seven days; on the first day there shall be a sabbath-rest, and on the eighth day a sabbath-rest. 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. 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.