1 Chronicles 23:28-31

28For their office is 1to assist the sons of Aaron with the service of the house of the Lord, 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,

292and with the showbread, and 3the fine flour for a grain offering, and unleavened wafers, or 4what is baked in the pan or 5what is well-mixed, and 6all measures of volume and size.

30They are to stand every morning to thank and to praise the Lord, and likewise at evening,

31and to offer all burnt offerings to the Lord, 7on the sabbaths, the new moons and 8the fixed festivals in the number set by the ordinance concerning them, continually before the Lord.