Numbers 3:29

The Levites, however, were not numbered among them by their fathers’ tribe.

“But you shall 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 attend to it; they shall also camp around the tabernacle.

“But the Levites shall camp around the tabernacle of the testimony so that there will be no wrath on the congregation of the sons of Israel. So the Levites shall keep charge of the tabernacle of the testimony.”

“Yet they shall be ministers in My sanctuary, having oversight at the gates of the house and ministering in the house; they shall slaughter the burnt offering and the sacrifice for the people, and they shall stand before them to minister to them.