Exodus 13:15 References

15 'It came about, when Pharaoh was stubborn about letting us go, that the aLord killed every firstborn in the land of Egypt, both the firstborn of man and the firstborn of beast. Therefore, I sacrifice to the Lord the males, the first offspring of every womb, but every firstborn of my sons I redeem.'

a Exodus 12:29

Exodus 12

29 Now it came about at amidnight that bthe Lord struck all cthe firstborn in the land of Egypt, from the firstborn of Pharaoh who sat on his throne to the firstborn of the captive who was in the dungeon, and all the firstborn of dcattle.