Numbers 4:35

from thirty years old and above, even to fifty years old, everyone who entered the service for work in the tabernacle of meeting;

Surrounding context

4:34 And Moses, Aaron, and the leaders of the congregation numbered the sons of the Kohathites by their families and by their fathers' house,

4:35 from thirty years old and above, even to fifty years old, everyone who entered the service for work in the tabernacle of meeting;

4:36 and those who were numbered by their families were two thousand seven hundred and fifty.

Translation and sources