Numbers 8:22-24

21st Century King James Version

²² And after that went the Levites in to do their service in the tabernacle of the congregation before Aaron and before his sons. As the Lord had commanded Moses concerning the Levites, so did they unto them.

²³ And the Lord spoke unto Moses, saying,

²⁴ “This is what applies unto the Levites: From twenty and five years old and upward they shall go in to wait upon the service of the tabernacle of the congregation.