Numbers 4:31-33

31And this is the charge of their burden, according to all their service in the tabernacle of the congregation; the boards of the tabernacle, and its bars, and its pillars, and its sockets, 32And the pillars around the court, and their sockets, and their pins, and their cords, with all their instruments, and with all their service: and by name ye shall reckon the instruments of the charge of their burden. 33This is the service of the families of the sons of Merari, according to all their service, in the tabernacle of the congregation, under the hand of Ithamar the son of Aaron the priest.