Deuteronomy 16:13-17

“You must observe the Festival of Shelters for seven days at the end of the harvest season, after the grain has been threshed and the grapes have been pressed. This festival will be a happy time of celebrating with your sons and daughters, your male and female servants, and the Levites, foreigners, orphans, and widows from your towns. For seven days you must celebrate this festival to honor the LORD your God at the place he chooses, for it is he who blesses you with bountiful harvests and gives you success in all your work. This festival will be a time of great joy for all. “Each year every man in Israel must celebrate these three festivals: the Festival of Unleavened Bread, the Festival of Harvest, and the Festival of Shelters. On each of these occasions, all men must appear before the LORD your God at the place he chooses, but they must not appear before the LORD without a gift for him. All must give as they are able, according to the blessings given to them by the LORD your God.