1 Chronicles 23:30-32

30And to stand every morning to thank and praise the Lord, and likewise at even;

31And to offer all burnt sacrifices unto the Lord in the sabbaths, in the new moons, and on the set feasts, by number, according to the order commanded unto them, continually before the Lord:

32And that they should keep the charge of the tabernacle of the congregation, and the charge of the holy place, and the charge of the sons of Aaron their brethren, in the service of the house of the Lord.