1 Chronicles 23:28-31

28The duty of the Levites was to help Aaron’s descendants in the service of the temple of the Lord: to be in charge of the courtyards, the side rooms, the purification of all sacred things and the performance of other duties at the house of God.

29They were in charge of the bread set out on the table, the special flour for the grain offerings, the thin loaves made without yeast, the baking and the mixing, and all measurements of quantity and size.

30They were also to stand every morning to thank and praise the Lord. They were to do the same in the evening

31and whenever burnt offerings were presented to the Lord on the Sabbaths, at the New Moon feasts and at the appointed festivals. They were to serve before the Lord regularly in the proper number and in the way prescribed for them.