At that time the Lord separated the tribe of Levi to bear the ark of the covenant of the Lord, to stand before the Lord to minister to Him and to bless in His name, to this day.
“And the tabernacle of meeting shall move out with the camp of the Levites in the middle of the camps; as they camp, so they shall move out, everyone in his place, by their standards.
and that they should attend to the needs of the tabernacle of meeting, the needs of the holy place, and the needs of the sons of Aaron their brethren in the work of the house of the Lord.
My sons, do not be negligent now, for the Lord has chosen you to stand before Him, to serve Him, and that you should minister to Him and burn incense.”
They assigned the priests to their divisions and the Levites to their divisions, over the service of God in Jerusalem, as it is written in the Book of Moses.
“Behold, I have given the children of Levi all the tithes in Israel as an inheritance in return for the work which they perform, the work of the tabernacle of meeting.
Then David said, “No one may carry the ark of God but the Levites, for the Lord has chosen them to carry the ark of God and to minister before Him forever.”
because their duty was to help the sons of Aaron in the service of the house of the Lord, in the courts and in the chambers, in the purifying of all holy things and the work of the service of the house of God,