Moses
Numbers 18:22ESV·traditional attribution

so that the people of Israel do not come near the tent of meeting, lest they bear sin and die.

John Calvin Reformed @genevareformer

22. Neither must the children of Israel. He again inculcates what he had before said, that the Levites were chosen to attend to the sacred things; since God would not admit all the people promiscuously, as before the giving of the Law, when others also offered the sacrifices.

Matthew Henry Presbyterian @wholebiblehenry

Here is a further account of the provision that was made both for the Levites and for the priests, out of the country. I. They must have no inheritance in the land; only cities to dwell in were afterwards allowed them, but no ground to occupy: Thou shalt not have any part among them, Num 18:20.

Commenting on Numbers 18:20-32

John Gill Reformed Baptist @doctorgill

But the Levites shall do the service of the tabernacle of the congregation,.... In guarding the tabernacle, that no unclean persons enter into it, or any others take anything out of it, and in assisting the priests in their service, and carrying the vessels of the sanctuary when required: and they shall bear their iniquity: that is, when they fail in the duty of their...