Numbers 4:22-28

22“Take 1a census of the sons of Gershon 2also, by their fathers’ households, by their families; 23from 3thirty years and upward to fifty years old, you shall 4number them; all who enter to perform the service to do the work in the tent of meeting. 24This is the service of the families of the Gershonites, in serving and in carrying: 25they shall carry 5the curtains of the tabernacle and the tent of meeting with its covering and 6the covering of porpoise skin that is on top of it, and the screen for the doorway of the tent of meeting, 26and 7the hangings of the court, and the screen for the doorway of the gate of the court which is around the tabernacle and the altar, and their cords and all the equipment for their service; and all that is to be done, 8they shall perform. 27All the service of the sons of the Gershonites, in all their loads and in all their work, shall be performed at the 9command of Aaron and his sons; and you shall assign to them as a duty all their loads. 28This is the service of the families of the sons of the Gershonites in the tent of meeting, and their duties shall be 10under the direction of Ithamar the son of Aaron the priest.