Deuteronomy 16:13-16

13Thou shalt observe the feast of tabernacles seven days, after that thou hast gathered in thy grain and thy wine:1

14And thou shalt rejoice in thy feast, thou, and thy son, and thy daughter, and thy male servant, and thy female servant, and the Levite, the stranger, and the fatherless, and the widow, that are within thy gates.

15Seven days shalt thou keep a solemn feast to the LORD thy God in the place which the LORD shall choose: because the LORD thy God shall bless thee in all thy increase, and in all the works of thy hands, therefore thou shalt surely rejoice.

16Three times in a year shall all thy males appear before the LORD thy God in the place which he shall choose; in the feast of unleavened bread, and in the feast of weeks, and in the feast of tabernacles: and they shall not appear before the LORD empty: