Deuteronomy 16:13-16

13“You shall observe the Feast of Tabernacles seven days, when you have gathered from your threshing floor and from your winepress.

14And you shall rejoice in your feast, you and your son and your daughter, your male servant and your female servant and the Levite, the stranger and the fatherless and the widow, who are within your gates.

15Seven days you shall keep a sacred feast to the Lord your God in the place which the Lord chooses, because the Lord your God will bless you in all your produce and in all the work of your hands, so that you surely rejoice.

16“Three times a year all your males shall appear before the Lord your God in the place which He chooses: at the Feast of Unleavened Bread, at the Feast of Weeks, and at the Feast of Tabernacles; and they shall not appear before the Lord empty-handed.