1 Chronicles 23:29-31

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.

30And they were to stand every morning, thanking and praising the Lord, and likewise at evening,

31and whenever burnt offerings were offered to the Lord on Sabbaths, new moons, and feast days, according to the number required of them, regularly before the Lord.