Numbers 4:29

"As for the sons of Merari, thou shalt number them by their families, by their fathers' houses; from thirty years old and upward even unto fifty years old thou shalt number them, every one that entereth upon the service, to do the work of the tent of meeting. 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 thereof, and the pillars thereof, and the sockets thereof, 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 ye shall appoint the instruments of the charge of their burden. 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."

Numbers 4:32 here indicates that all of the assignments for the handling and transport of the vast amount of material in the tabernacle were made on an individual and personal basis, "by name." The need for this appears in the fact that some would have chosen lighter burdens than were appropriate, and that others might have sought to handle or carry the more sacred items, leading to strife and jealousies unless all such decisions had been taken out of the hands of the Levites and made the responsibility of the priests.

Numbers 4:34-49 of this chapter give the detail of the numbering of the families of the Kohathites, the Gershonites, and the Merarites, repeating over and over again the same formula. Numbers 4:34-36 show what is repeated.