Numbers 3:30-34

and the leader of the fathers’ households of the Kohathite families: Elizaphan the son of Uzziel.

Now their duties included the ark, the table, the lampstand, the altars, the utensils of the sanctuary with which they minister, the curtain, and all the service concerning them;

and Eleazar the son of Aaron the priest was the head of the leaders of Levi, and he had the supervision of those who performed the duties of the sanctuary.

Of Merari was the family of the Mahlites and the family of the Mushites; these were the families of Merari.

Their numbered men in the counting of every male from a month old and upward: 6,200.