From thirty years old and upward until 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 it that belongs to the Levites: from twenty and five years old and upward they shall go in to wait on the service of the tabernacle of the congregation:
But shall minister with their brothers in the tabernacle of the congregation, to keep the charge, and shall do no service. Thus shall you do to the Levites touching their charge.