1 Chronicles 23:26

24These were the sons of Levi after their fathers’ houses, even the heads of the fathers’ houses of those who were counted individually, in the number of names by their polls, who did the work for the service of the LORD’s house, from twenty years old and upward.

25For David said, “The LORD, the God of Israel, has given rest to his people; and he dwells in Jerusalem forever.

26Also the Levites will no longer need to carry the tabernacle and all its vessels for its service.”

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

28For their duty was to wait on the sons of Aaron for the service of the LORD’s house—in the courts, in the rooms, and in the purifying of all holy things, even the work of the service of God’s house;