When Pharaoh stubbornly refused to let us go, the LORD killed all the firstborn in the land of Egypt, both the firstborn of man, and the firstborn of livestock.
Therefore I sacrifice to the LORD all that opens the womb, being males; but all the firstborn of my sons I redeem.’ It shall be for a sign on your hand, and for symbols between your eyes; for by strength of hand the LORD brought us out of Egypt.”