Numbers 3:44-46

Revised Standard Version

⁴⁴ And the Lord said to Moses, ⁴⁵ “Take the Levites instead of all the first-born among the people of Israel, and the cattle of the Levites instead of their cattle; and the Levites shall be mine: I am the Lord. ⁴⁶ And for the redemption of the two hundred and seventy-three of the first-born of the people of Israel, over and above the number of the male Levites,