Numbers

And I, behold, I have taken your brethren the Levites from among the children of Israel: to you they are given as a gift for the Lord, to do the service of the tabernacle of the congregation.

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 that they should keep the charge of the tabernacle of the congregation, and the charge of the holy place, and the charge of the sons of Aaron their brethren, in the service of the house of the Lord.

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.

Therefore thou and thy sons with thee shall keep your priest’s office for every thing of the altar, and within the vail; and ye shall serve: I have given your priest’s office unto you as a service of gift: and the stranger that cometh nigh shall be put to death.