King James Version
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:English Standard Version
from thirty years old up to fifty years old, everyone who could come on duty, for service in the tent of meeting;Catholic Public Domain Version
from thirty years and above, even to the fiftieth year, of all who enter to the ministry of the tabernacle of the covenant