Numbers 4:33

33 This 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.”

Read Numbers 4:33 Using Other Translations

This is the service of the families of the sons of Merari, according to all their service, in the tabernacle of the congregation, under the hand of Ithamar the son of Aaron the priest.
This is the service of the clans of the sons of Merari, the whole of their service in the tent of meeting, under the direction of Ithamar the son of Aaron the priest."
So these are the duties of the Merarite clans at the Tabernacle. They are directly responsible to Ithamar son of Aaron the priest.”