“Now, the fifteenth day of the seventh month, when you have gathered in the produce of the land, you shall keep the festival of Yahweh lasting seven days. There is a complete rest on the first day and a complete rest on the eighth day. On the first day you shall take the fruit of the majestic trees, branches of palm trees, boughs of leafy trees, and willows of the brook. You shall rejoice before Yahweh your God for seven days. You shall keep it as a festival to Yahweh seven days in the year. You shall keep it in the seventh month as a statute forever throughout your generations. You shall live in tents or booths for seven days. All that are citizens in Israel shall live in tents or booths, so that your generations may know that I made the people of Israel live in tents or booths when I brought them out of the land of Egypt. I am Yahweh your God. Thus Moses declared to the people of Israel the appointed festivals of Yahweh.”
This is really the 7 day festival of tents or booths with more details. This is a 7 day joyful remembrance of the tent living in the desert. There is complete rest on the 1st and the 8th days. You take the fruit of the trees, the branches of palm trees, the boughs of leafy trees, and the willows of the brook, probably to build your tent. You rejoice before Yahweh for 7 days. You live in these tents or booths for 7 days. Every citizen in Israel had to live in these tents or booths, so that future generations might know what it was like when the people of Israel lived in these tents or booths when they left Egypt. Thus Moses declared to the people of Israel the various festivals of Yahweh.