From thirty years old and upward up to fifty years old shall you number them; all that enter in to perform the service, to do the work in the tabernacle of the congregation.
This is the work that belongs to the Levites: from twenty five years old and upward they shall go in to wait upon the service of the tabernacle of the congregation:
But shall minister with their brethren in the tabernacle of the congregation, to fulfill their responsibilities, and shall do no service. Thus shall you do unto the Levites concerning their duties.