1 Chronicles 23:24-32

²⁴ These 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 house of Yahweh, from twenty years old and upward. ²⁵ For David said, Yahweh, the God of Israel, has given rest to his people; and he dwells in Jerusalem forever: ²⁶ and also the Levites shall no more have need to carry the tabernacle and all its vessels for its service. ²⁷ For by the last words of David the sons of Levi were numbered, from twenty years old and upward. ²⁸ For their office was to wait on the sons of Aaron for the service of the house of Yahweh, in the courts, and in the chambers, and in the purifying of all holy things, even the work of the service of the house of God; ²⁹ for the show bread also, and for the fine flour for a meal offering, whether of unleavened wafers, or of that which is baked in the pan, or of that which is soaked, and for all manner of measure and size; ³⁰ and to stand every morning to thank and praise Yahweh, and likewise in the evening; ³¹ and to offer all burnt offerings to Yahweh, on the Sabbaths, on the new moons, and on the set feasts, in number according to the ordinance concerning them, continually before Yahweh; ³² and that they should keep the duty of the Tent of Meeting, and the duty of the holy place, and the duty of the sons of Aaron their brothers, for the service of the house of Yahweh.