Numbers 8:5-26

MLV(i) 5 And Jehovah spoke to Moses, saying, 6 Take the Levites from among the sons of Israel and cleanse them. 7 And thus you will do to them to cleanse them: sprinkle the water of expiation upon them and let them cause a razor to pass over all their flesh and let them wash their clothes and cleanse themselves. 8 Then let them take a young bullock and its meal offering–fine flour mingled with oil. And you will take another young bullock for a sin offering. 9 And you will present the Levites before the tent of meeting. And you will assemble the whole congregation of the sons of Israel, 10 and you will present the Levites before Jehovah. And the sons of Israel will lay their hands upon the Levites.
11 And Aaron will offer the Levites before Jehovah for a wave offering from the sons of Israel, that it may be theirs to do the service of Jehovah. 12 And the Levites will lay their hands upon the heads of the bullocks and offer you the one for a sin offering and the other for a burnt offering, to Jehovah, to make atonement for the Levites. 13 And you will set the Levites before Aaron and before his sons and offer them for a wave offering to Jehovah. 14 Thus will you separate the Levites from among the sons of Israel and the Levites will be mine. 15 And after that the Levites will go in to do the service of the tent of meeting. And you will cleanse them and offer them for a wave offering.
16 For they are entirely given to me from among the sons of Israel; instead of all who open the womb, even the firstborn of all the sons of Israel, I have taken them to me. 17 For all the firstborn among the sons of Israel are mine, both man and beast. On the day that I killed* all the firstborn in the land of Egypt I made them holy for myself. 18 And I have taken the Levites instead of all the firstborn among the sons of Israel. 19 And I have given the Levites as a gift to Aaron and to his sons from among the sons of Israel, to do the service of the sons of Israel in the tent of meeting and to make atonement for the sons of Israel, that there is no plague among the sons of Israel, when the sons of Israel come near to the sanctuary.
20 Thus did Moses and Aaron and all the congregation of the sons of Israel, to the Levites. According to all that Jehovah commanded Moses concerning the Levites, so the sons of Israel did to them. 21 And the Levites purified themselves from sin and they washed their clothes. And Aaron offered them for a wave offering before Jehovah 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 before Aaron and before his sons. As Jehovah had commanded Moses concerning the Levites, so they did to them.
23 And Jehovah spoke to Moses, saying, 24 This is what belongs to the Levites: From twenty-five years old and upward they will go in to wait upon the service in the work of the tent of meeting. 25 And from the age of fifty years they will cease waiting upon the work and will serve no more, 26 but will minister with their brothers in the tent of meeting, to keep the charge and will do no service. Thus will you do to the Levites concerning their charges.