15 Only then shall the Levites enter upon their service in the tent of meeting, when you have cleansed them and presented them as an elevated offering.
16 For they, among the Israelites, are totally dedicated to me; I have taken them for myself in place of everyone that opens the womb, the firstborn of all the Israelites.
17 Indeed, all the firstborn among the Israelites, human being and beast alike, belong to me; I consecrated them to myself on the day I killed all the firstborn in the land of Egypt.
18 But I have taken the Levites in place of all the firstborn Israelites;
19 and from among the Israelites I have given to Aaron and his sons these Levites, who are to be dedicated, to perform the service of the Israelites in the tent of meeting and to make atonement for them, so that no plague may strike among the Israelites should they come too near the sanctuary.
20 This, then, is what Moses and Aaron and the whole community of the Israelites did with respect to the Levites; the Israelites did exactly as the Lord had commanded Moses concerning them.
21 When the Levites had purified themselves and washed their garments, Aaron presented them as an elevated offering before the Lord, and made atonement for them to cleanse them.