Numbers 4:41-43

American Standard Version

⁴¹ These are they that were numbered of the families of the sons of Gershon, all that did serve in the tent of meeting, whom Moses and Aaron numbered according to the commandment of Jehovah.

⁴² And those that were numbered of the families of the sons of Merari, by their families, by their fathers’ houses, ⁴³ from thirty years old and upward even unto fifty years old, every one that entered upon the service, for work in the tent of meeting,