Numbers 4:16, 28, 33

“And Eleazar the son of Aaron the priest shall have charge of the oil for the light, the fragrant incense, the regular grain offering, and the anointing oil, with the oversight of the whole tabernacle and all that is in it, of the sanctuary and its vessels.”

This is the service of the clans of the sons of the Gershonites in the tent of meeting, and their guard duty is to be under the direction 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.”