Numbers 3:44-46

Darby Translation

⁴⁴ And Jehovah spoke to Moses, saying,

⁴⁵ Take the Levites instead of all the firstborn among the children of Israel, and the cattle of the Levites instead of their cattle; and the Levites shall be mine: I am Jehovah.

⁴⁶ And for those that are to be ransomed, the two hundred and seventy-three of the firstborn of the children of Israel, which are in excess over the Levites,