Numbers 4:6

“So when the tabernacle is to set out, the Levites shall take it down; and when the tabernacle encamps, the Levites shall set it up. But the layman who comes near shall be put to death.

they shall carry the curtains of the tabernacle and the tent of meeting with its covering and the covering of porpoise skin that is on top of it, and the screen for the doorway of the tent of meeting,

But he did not give any to the sons of Kohath because theirs was the service of the holy objects, which they carried on the shoulder.

Then the Kohathites set out, carrying the holy objects; and the tabernacle was set up before their arrival.

So Moses wrote this law and gave it to the priests, the sons of Levi who carried the ark of the covenant of Yahweh, and to all the elders of Israel.

And the sons of the Levites carried the ark of God on their shoulders with the poles thereon, as Moses had commanded according to the word of Yahweh.

And the Levites were numbered from thirty years old and upward, and their number by census of men was 38,000.

“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.