Deuteronomy 16:13-17

13You must celebrate the Festival of Temporary Shelters for seven days, at the time of the grain and grape harvest.

14You are to rejoice in your festival, you, your son, your daughter, your male and female slaves, the Levites, the resident foreigners, the orphans, and the widows who are in your villages.

15You are to celebrate the festival seven days before the Lord your God in the place he chooses, for he will bless you in all your productivity and in whatever you do; so you will indeed rejoice!

16Three times a year all your males must appear before the Lord your God in the place he chooses for the Festival of Unleavened Bread, the Festival of Weeks, and the Festival of Temporary Shelters; and they must not appear before him empty-handed.

17Every one of you must give as you are able, according to the blessing of the Lord your God that he has given you.