Numbers 4:33-35

Darby Translation

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.

³⁴ And Moses and Aaron and the princes of the assembly numbered the sons of the Kohathites after their families, and according to their fathers' houses,

³⁵ from thirty years old and upward even to fifty years old, every one that entered into the labour, for service in the tent of meeting.