Numbers 4:25-27

25they shall carry 1the curtains of the tabernacle and the tent of meeting with its covering and 2the covering of porpoise skin that is on top of it, and the screen for the doorway of the tent of meeting,

26and 3the 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, 4they 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 5command of Aaron and his sons; and you shall assign to them as a duty all their loads.