Here are the amounts of the metals used for the holy tent, where the tablets of the covenant law were kept. Moses commanded the Levites to record the amounts. The Levites did the work under the direction of Ithamar. Ithamar was the son of Aaron the priest.
All their work must be done under the direction of Aaron and his sons. That includes carrying and everything else they do. Aaron and his sons must tell them what to carry. And that will be their work.
That is the work the families of Merari must do at the tent of meeting. They must work under the direction of Ithamar the priest. He is the son of Aaron.”