Numbers 4:29-33

29“Count the Merarites by their clans and families. 30Count all the men from thirty to fifty years of age who come to serve in the work at the tent of meeting. 31As part of all their service at the tent, they are to carry the frames of the tabernacle, its crossbars, posts and bases, 32as well as the posts of the surrounding courtyard with their bases, tent pegs, ropes, all their equipment and everything related to their use. Assign to each man the specific things he is to carry. 33This is the service of the Merarite clans as they work at the tent of meeting under the direction of Ithamar son of Aaron, the priest.”