17. For all the firstborn of the Israelites are Mine, both of man and beast; on the day that I smote every firstborn in the land of Egypt [not of Israel], I consecrated them and set them apart for Myself.
18. And I have taken the Levites instead of all the firstborn of the Israelites.
19. And I have given the Levites as a gift to Aaron and to his sons from among the Israelites to do the service of the Israelites at the Tent of Meeting and to make atonement for them, that there may be no plague among the Israelites if they should come near the sanctuary.
20. So Moses and Aaron and all the congregation of the Israelites did thus to the Levites; according to all that the Lord commanded Moses concerning [them], so did the Israelites to them.
21. The Levites cleansed and purified themselves and they washed their clothes; and Aaron offered them as a wave offering before the Lord and Aaron made atonement for them to cleanse them.
22. And after that the Levites went in to do their service in the Tent of Meeting with the attendance of Aaron and his sons; as the Lord had commanded Moses concerning the Levites, so did they to them.
23. And the Lord said to Moses,
24. This is what applies to the Levites: from twenty-five years old and upward they shall go in to perform the work of the service of the Tent of Meeting,
25. And at the age of fifty years, they shall retire from the warfare of the service and serve no more,
26. But shall help their brethren in the Tent of Meeting [attend to protecting the sacred things from being profaned], but shall do no regular or heavy service. Thus shall you direct the Levites in regard to their duties.