Deuteronomy 16:13-17

13“You are to celebrate the Festival of Shelters for seven days when you have gathered in everything from your threshing floor and winepress.

14Rejoice during your festival — you, your son and daughter, your male and female slave, as well as the Levite, the resident alien, the fatherless, and the widow within your city gates.

15You are to hold a seven-day festival for the Lord your God in the place he chooses, because the Lord your God will bless you in all your produce and in all the work of your hands, and you will have abundant joy.

16“All your males are to appear three times a year before the Lord your God in the place he chooses: at the Festival of Unleavened Bread, the Festival of Weeks, and the Festival of Shelters. No one is to appear before the Lord empty-handed.

17Everyone must appear with a gift suited to his means, according to the blessing the Lord your God has given you.