Numbers 3:10-12

Douay-Rheims 1899 American Edition

¹⁰ To Aaron and to his sons, to whom they are delivered by the children of Israel. But thou shalt appoint Aaron and his sons over the service of priesthood. The stranger that approacheth to minister, shall be put to death.

¹¹ And the Lord spoke to Moses, saying:

¹² I have taken the Levites from the children of Israel, for every firstborn that openeth the womb among the children of Israel, and the Levites shall be mine.