Numbers 4:21-33

Then the LORD spoke to Moses, saying, “Take a census of the sons of Gershon also, by their fathers’ households, by their families. From thirty years and upward to fifty years old, you shall number them; all who enter for service to do the work in the Tent of Meeting. This is the service of the families of the Gershonites, in serving and in carrying [when on the march]: they shall carry the tent curtains of the tabernacle, and the Tent of Meeting, its covering and the covering of porpoise skin (fine leather) that is on top of it, and the curtain for the doorway of the Tent of Meeting (tabernacle), and the hangings of the courtyard, and the curtain for the entrance of the gate of the courtyard which is around the tabernacle and the altar, and their tent ropes, and all the equipment for their service; and all that is to be done, they shall perform. Aaron and his sons shall direct all the service of the sons of the Gershonites, all they have to carry and all they have to do. You shall assign to them as a duty all that they are to carry [on the march]. This is the service of the families of the sons of Gershon in the Tent of Meeting (tabernacle); and their duties shall be under the direction of Ithamar the son of Aaron, the [high] priest. “As for the sons of Merari, you shall number them by their families (clans), by their fathers’ households; from thirty years and upward to fifty years old, you shall number them, everyone who enters the service to do the work of the Tent of Meeting (tabernacle). This is what they are assigned to carry [on the march], according to all their service in the Tent of Meeting: the boards [for the framework] of the tabernacle and its bars and its pillars and its sockets or bases, and the pillars around the courtyard with their sockets or bases and their pegs and their cords (tent ropes), with all their equipment and with all their [accessories for] service; and you shall assign each man by name the items he is to carry [on the march]. This is the work of the families of the sons of Merari, according to all their tasks in the Tent of Meeting (tabernacle), under the direction of Ithamar the son of Aaron, the priest.”