Leviticus 23:39-41

39“So on the fifteenth day of the seventh month, when you have gathered in the fruits of the land, you are to keep the Feast of Adonai for seven days. The first day is to be a Shabbat rest, and the eighth day will also be a Shabbat rest.

40On the first day you are to take choice fruit of trees, branches of palm trees, boughs of leafy trees, and willows of the brook, and rejoice before Adonai your God for seven days.

41You are to celebrate it as a festival to Adonai for seven days in the year. It is a statute forever throughout your generations—you are to celebrate it in the seventh month.