Numbers Chapter 8 Verse 21And the Levites were purified, and they washed their clothes; and Aaron offered them [as] an offering before the LORD; and Aaron made an atonement for them to cleanse them.

And Aaron shall offer the Levites before the LORD [for] an offering of the children of Israel, that they may execute the service of the LORD.

And the Levites shall lay their hands upon the heads of the bullocks: and thou shalt offer the one [for] a sin offering, and the other [for] a burnt offering, unto the LORD, to make an atonement for the Levites.

And thou shalt set the Levites before Aaron, and before his sons, and offer them [for] an offering unto the LORD.

Thus shalt thou separate the Levites from among the children of Israel: and the Levites shall be mine.

And after that shall the Levites go in to do the service of the tabernacle of the congregation: and thou shalt cleanse them, and offer them [for] an offering.

For they [are] wholly given unto me from among the children of Israel; instead of such as open every womb, [even instead of] the firstborn of all the children of Israel, have I taken them unto me.

For all the firstborn of the children of Israel [are] mine, [both] man and beast: on the day that I smote every firstborn in the land of Egypt I sanctified them for myself.

And I have taken the Levites for all the firstborn of the children of Israel.

And I have given the Levites [as] a gift to Aaron and to his sons from among the children of Israel, to do the service of the children of Israel in the tabernacle of the congregation, and to make an atonement for the children of Israel: that there be no plague among the children of Israel, when the children of Israel come nigh unto the sanctuary.

And Moses, and Aaron, and all the congregation of the children of Israel, did to the Levites according unto all that the LORD commanded Moses concerning the Levites, so did the children of Israel unto them.

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.

And the LORD spake unto Moses, saying,

This [is it] that [belongeth] 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:

And from the age of fifty years they shall cease waiting upon the service [thereof], and shall serve no more:

But shall minister with their brethren in the tabernacle of the congregation, to keep the charge, and shall do no service. Thus shalt thou do unto the Levites touching their charge.

And the LORD spake unto Moses in the wilderness of Sinai, in the first month of the second year after they were come out of the land of Egypt, saying,

Let the children of Israel also keep the passover at his appointed season.

In the fourteenth day of this month, at even, ye shall keep it in his appointed season: according to all the rites of it, and according to all the ceremonies thereof, shall ye keep it.

And Moses spake unto the children of Israel, that they should keep the passover.

And they kept the passover on the fourteenth day of the first month at even in the wilderness of Sinai: according to all that the LORD commanded Moses, so did the children of Israel.

The Book of Numbers, Chapter 8, Verse 21