Numbers 4:28-30

Darby Translation

²⁸ This is the service of the families of the sons of Gershon in the tent of meeting, and their charge shall be under the hand of Ithamar the son of Aaron the priest.

²⁹ The sons of Merari: after their families, according to their fathers' houses shalt thou number them;

³⁰ from thirty years old and upward even to fifty years old shalt thou number them, every one that entereth into the labour, to perform the service of the tent of meeting.