Numbers 3:13

13 All the firstborn males belong to me, because on the day that I killed all the firstborn males in the land of Egypt, I separated for myself all the firstborn males in Isra'el, both human and animal. They are mine; I am ADONAI."

Numbers 3:13 In-Context

11 ADONAI said to Moshe,
12 "I have taken the L'vi'im from among the people of Isra'el in lieu of every firstborn male that is first from the womb among the people of Isra'el; the L'vi'im are to be mine.
13 All the firstborn males belong to me, because on the day that I killed all the firstborn males in the land of Egypt, I separated for myself all the firstborn males in Isra'el, both human and animal. They are mine; I am ADONAI."
14 ADONAI said to Moshe in the Sinai Desert,
15 "Take a census of the tribe of Levi by clans and families. Count every male a month old or over."
Complete Jewish Bible Copyright 1998 by David H. Stern. Published by Jewish New Testament Publications, Inc. All rights reserved. Used by permission.