Numbers 4:34

31 This is the charge of their burden, according to all their service in the tent of meeting: the boards of the tent, and the bars of it, and the pillars of it, and the sockets of it,

32 and the pillars of the court round about, and their sockets, and their pins, and their cords, with all their instruments, and with all their service: and by name you shall appoint the instruments of the charge of their burden.

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.

34 Moses and Aaron and the princes of the congregation numbered the sons of the Kohathites by their families, and by their fathers` houses,

35 from thirty years old and upward even to fifty years old, everyone who entered on the service, for work in the tent of meeting:

36 and those who were numbered of them by their families were two thousand seven hundred fifty.

37 These are those who were numbered of the families of the Kohathites, all who did serve in the tent of meeting, whom Moses and Aaron numbered according to the commandment of Yahweh by Moses.