TSK · Numbers 3:6

then Moses stood in the gate of the camp, and said, "Whoever is on Yahweh's side, come to me!" All the sons of Levi gathered themselves together to him.

but appoint the Levites over the Tabernacle of the Testimony, and over all its furnishings, and over all that belongs to it. They shall carry the tabernacle, and all its furnishings; and they shall take care of it, and shall encamp around it.

But the Levites were not numbered among the children of Israel; as Yahweh commanded Moses.

For they are wholly given to me from among the children of Israel; instead of all who open the womb, even the firstborn of all the children of Israel, I have taken them to me.

Is it a small thing to you, that the God of Israel has separated you from the congregation of Israel, to bring you near to himself, to do the service of the tabernacle of Yahweh, and to stand before the congregation to minister to them;

Yahweh said to Aaron, "You and your sons and your fathers' house with you shall bear the iniquity of the sanctuary; and you and your sons with you shall bear the iniquity of your priesthood.

I, behold, I have taken your brothers the Levites from among the children of Israel: to you they are a gift, given to Yahweh, to do the service of the Tent of Meeting.

At that time Yahweh set apart the tribe of Levi, to bear the ark of the covenant of Yahweh, to stand before Yahweh to minister to him, and to bless in his name, to this day.

These are those who waited, and their sons. Of the sons of the Kohathites: Heman the singer, the son of Joel, the son of Samuel,

For their office was to wait on the sons of Aaron for the service of the house of Yahweh, in the courts, and in the rooms, and in the purifying of all holy things, even the work of the service of the house of God;

They set the priests in their divisions, and the Levites in their courses, for the service of God, which is at Jerusalem; as it is written in the book of Moses.