Num Numbers, chapter Book of Numbers, chapter 3
And I, behold, I have taken the Levites from among the children of Israel instead of all the first-born that openeth the womb among the children of Israel; and the Levites shall be mine: Exo 29:24; Num 8:16for all the first-born are mine; on the day that I smote all the first-born in the land of Egypt I hallowed unto me all the first-born in Israel, both man and beast; mine they shall be: I am Jehovah.Exo 13:2; Exo 22:29; Exo 34:19; Lev 27:26; Num 8:17; Luk 2:23