Numbers 4:33

4:33 This is the service of the families of the Merarites, their entire service concerning the tent of meeting, under the authority of Ithamar son of Aaron the priest.”

Numbers 4:45

4:45 These are those numbered from the families of the Merarites, whom Moses and Aaron numbered according to the word of the Lord by the authority of Moses.

Numbers 7:8

7:8 and he gave four carts and eight oxen to the Merarites, as their service required, under the authority of Ithamar son of Aaron the priest.