1 Chronicles 23:26-29

26And so the Levites no longer need to carry the tabernacle or any of the things for its service."

27For by the last words of David the sons of Levi were numbered from twenty years old and upward.

28For their duty was to assist the sons of Aaron for the service of the house of the Lord, having the care of the courts and the chambers, the cleansing of all that is holy, and any work for the service of the house of God.

29Their duty was also to assist with the showbread, the flour for the grain offering, the wafers of unleavened bread, the baked offering, the offering mixed with oil, and all measures of quantity or size.