Numbers 3:38

3:38 But those who were to camp in front of the tabernacle on the east, in front of the tent of meeting, were Moses, Aaron, and his sons. They were responsible for the needs of the sanctuary and for the needs of the Israelites, but the unauthorized person who approached was to be put to death.

Numbers 4:15

4:15 “When Aaron and his sons have finished covering the sanctuary and all the furnishings of the sanctuary, when the camp is ready to journey, then the Kohathites will come to carry them; but they must not touch any holy thing, or they will die. These are the responsibilities of the Kohathites with the tent of meeting.

Numbers 4:19

4:19 but in order that they will live and not die when they approach the most holy things, do this for them: Aaron and his sons will go in and appoint each man to his service and his responsibility.

Numbers 4:27

4:27 “All the service of the Gershonites, whether carrying loads or for any of their work, will be at the direction of Aaron and his sons. You will assign them all their tasks as their responsibility.