Numbers 4:29-33

MLV(i) 29 As for the sons of Merari, you will number them by their families, by their fathers' houses. 30 From thirty years old and upward even to fifty years old you will number them, each man who enters upon the service, to do the work of the tent of meeting.
31 And this is the charge of their burden, according to all their service in the tent of meeting: the boards of the tabernacle and the bars of it and the pillars of it and the sockets of it, 32 and the pillars of the court all around and their sockets and their pegs and their cords, with all their instruments and with all their service. And you* will appoint the instruments of the charge of their burden by name. 33 This is the service of the families of the sons of Merari, according to all their service, in the tent of meeting, under the hand of Ithamar the son of Aaron the priest.