Numbers 4:33-35

Modern English Version

³³ This is the service of the families of the sons of Merari, according to all their service, in the tent of meeting, under the hand of Ithamar the son of Aaron the priest.

Census of the Levites

³⁴ Moses, Aaron, and the leaders of the congregation numbered the sons of the Kohathites by their families, and by the house of their fathers, ³⁵ from thirty years old and older to fifty years old, everyone who entered into the service, for the work in the tent of meeting.