Exodus 13:15

In Egypt, Pharaoh was stubborn and refused to let us leave. So the LORD killed every firstborn in all the land. (The Lord killed the firstborn males—animal and human.) That is why I give every firstborn male animal to the killed every firstborn in all the land. (The Lord killed the firstborn males—animal and human.) That is why I give every firstborn male animal to the LORD, and that is why I buy back each of my firstborn sons from him.’