Numbers 4:35

from five and twenty years old and upwards to the age of fifty years, every one that goes in to minister and do service in the tabernacle of witness.

From thirty years old and upward even unto fifty years old, every one that entereth into the service, for the work in the tabernacle of the congregation:

from thirty years old and upward even to fifty years old, everyone who entered into the service for work in the Tent of Meeting.