Again the Lord spoke to Moses, saying,
Then you will know that I have sent this commandment to you, so that My covenant may continue with Levi,” says the Lord of armies.
So you shall appoint Aaron and his sons that they may keep their priesthood, but the layman who comes near shall be put to death.”
“Now, behold, I have taken the Levites from among the sons of Israel instead of every firstborn, the firstborn of the womb among the sons of Israel. So the Levites shall be Mine.