These were the sons of Levi by their ancestral houses-the heads of families, according to their registration by name in the headcount-20 years old or more, who worked in the service of the Lord's temple.
For David said, "The Lord God of Israel has given rest to His people, and He has come to stay in Jerusalem forever.
Also, the Levites no longer need to carry the tabernacle or any of the equipment for its service"-
for according to the last words of David, the Levites 20 years old or more were to be counted-
"but their duty will be to assist the sons of Aaron with the service of the Lord's temple, being responsible for the courts and the chambers, the purification of all the holy things, and the work of the service of God's temple-
as well as the rows [of the bread of the Presence], the fine flour for the grain offering, the wafers of unleavened bread, the baking, the mixing, and all measurements of volume and length.
References for 1 Chronicles 23:29
They are also to stand every morning to give thanks and praise to the Lord, and likewise in the evening.
Whenever burnt offerings are offered to the Lord on the Sabbaths, New Moons, and appointed festivals, they are to do so regularly in the Lord's presence according to the number prescribed for them.
They are to carry out their responsibilities to the tent of meeting, to the holy place, and to their relatives, the sons of Aaron, in the service of the Lord's temple."