Deuteronomy 16:15

12 And thou shalt remember that thou wast a bondman in Egypt: and thou shalt observe and do these statutes.

13 Thou shalt keep the feast of tabernacles seven days, after that thou hast gathered in from thy threshing-floor and from thy winepress:

14 and thou shalt rejoice in thy feast, thou, and thy son, and thy daughter, and thy man-servant, and thy maid-servant, and the Levite, and the sojourner, and the fatherless, and the widow, that are within thy gates.

15 Seven days shalt thou keep a feast unto Jehovah thy God in the place which Jehovah shall choose; because Jehovah thy God will bless thee in all thine increase, and in all the work of thy hands, and thou shalt be altogether joyful.

16 Three times in a year shall all thy males appear before Jehovah 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 Jehovah empty:

17 every man shall give as he is able, according to the blessing of Jehovah thy God which he hath given thee.

18 Judges and officers shalt thou make thee in all thy gates, which Jehovah thy God giveth thee, according to thy tribes; and they shall judge the people with righteous judgment.