Numbers 4:16, 28, 33

“The responsibility of Eleazar the son of Aaron the priest is the oil for the light and the fragrant incense and the continual grain offering and the anointing oil—the responsibility of all the tabernacle and of all that is in it, with the sanctuary and its furnishings.”

This is the service of the families of the sons of the Gershonites in the tent of meeting, and their duties shall be under the direction of Ithamar the son of Aaron the priest.

This is the service of the families of the sons of Merari, according to all their service in the tent of meeting, under the direction of Ithamar the son of Aaron the priest.”