Numbers 3:13

Overview - Numbers 3
The sons of Aaron.
The Levites are given to the priests instead of the first-born;
14 are numbered by their families.
21 The families, number, and charge of the Gershonites;
27 of the Kohathites;
33 of the Merarites.
38 The place and charge of Moses and Aaron.
40 The first-born are freed by the Levites.
44 The overplus are redeemed.
Treasury of Scripture Knowledge

Numbers 3:13  (King James Version)
Because all the firstborn are mine; for on the day that I smote all the firstborn in the land of Egypt I hallowed unto me all the firstborn in Israel, both man and beast: mine shall they be: I am the LORD.

Numbers 8:16 Numbers 8:17 18:15 Exodus 13:2 Exodus 13:12 ; 22:29 34:19 Leviticus 27:26 ; Ezekiel 44:30
Luke 2:23 ; Hebrews 12:23

on the day
Exodus 12:29 Exodus 12:30 ; 13:15