Leviticus 23:39-43

³⁹However on the fifteenth day of the seventh month, when you have gathered in the fruits of the land, you shall keep the feast of Yahweh seven days: on the first day shall be a solemn rest, and on the eighth day shall be a solemn rest. ⁴⁰You shall take on the first day the fruit of goodly trees, branches of palm-trees, and boughs of thick trees, and willows of the brook; and you shall rejoice before Yahweh your God seven days. ⁴¹You shall keep it a feast to Yahweh seven days in the year: it is a statute forever throughout your generations; you shall keep it in the seventh month. ⁴²You shall dwell in booths seven days; all who are home-born in Israel shall dwell in booths; ⁴³that 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 Yahweh your God.