Numbers 8:20-26
English Standard Version
Chapter 8
20Thus did Moses and Aaron and all the congregation of the people of Israel to the Levites. According to all that the Lord commanded Moses concerning the Levites, the people of Israel did to them. 21And the Levites purified themselves from sin and washed their clothes, and Aaron offered them as a wave offering before the Lord, and Aaron made atonement for them to cleanse them. 22And after that the Levites went in to do their service in the tent of meeting before Aaron and his sons; as the Lord had commanded Moses concerning the Levites, so they did to them.
23And the Lord spoke to Moses, saying,
24"This applies to the Levites: from twenty-five years old and upward they shall come to do duty in the service of the tent of meeting.
25And from the age of fifty years they shall withdraw from the duty of the service and serve no more.
26They minister to their brothers in the tent of meeting by keeping guard, but they shall do no service. Thus shall you do to the Levites in assigning their duties."
