Thematic Bible: Tribe of levi taken instead of the first-born

And the LORD spake unto Moses, saying, "Behold, I have taken the Levites, from among the children of Israel, for all the firstborn that openeth the matrix among the children of Israel: so that the Levites shall be mine. Because all the firstborn are mine - for the same day that I smote all the firstborn in the land of Egypt, I hallowed unto me all the firstborn in Israel, both man and beast, and mine they shall be: for I am the LORD."