Deuteronomy 16:14-18

And thou shalt rejoice in thy feast, thou, and thy son, and thy daughter, and thy manservant, and thy maidservant, and the Levite, the stranger, and the fatherless, and the widow, that are within thy gates.

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

Three 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:

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

Judges and officers shalt thou make thee in all thy gates, which the LORD thy God giveth thee, throughout thy tribes: and they shall judge the people with just judgment.