Numbers 8:20-26 - The Levites Are Dedicated To The Lord

²⁰ Thus Moses and Aaron and all the congregation of the children of Israel did [these things] to the Levites; in accordance with all that the Lord had commanded Moses concerning the Levites, so the Israelites did to them. ²¹ The Levites, too, purified themselves from sin and they washed their clothes; and Aaron presented them as a wave offering before the Lord, and Aaron made atonement for them to cleanse them. ²² Then after that the Levites went in to perform their service in the Tent of Meeting before Aaron and his sons; just as the Lord had commanded Moses concerning the Levites, so they did to them.

²³ Now the Lord spoke to Moses, saying, ²⁴ “This is what applies to the Levites: from twenty-five years old and upward they shall enter to perform service in the work of the Tent of Meeting, ²⁵ but at the age of fifty years, they shall retire from the service of the [tabernacle] work and serve no longer. ²⁶ They may assist their brothers in the Tent of Meeting to keep an obligation, but they shall do no [heavy or difficult] work. Thus you shall deal with the Levites concerning their obligations.”