Exodus 13:14-16

MSB(i) 14 In the future, when your son asks you, ‘What does this mean?’ you are to tell him, ‘With a mighty hand the LORD brought us out of Egypt, out of the house of slavery. 15 And when Pharaoh stubbornly refused to let us go, the LORD killed every firstborn in the land of Egypt, both of man and beast. This is why I sacrifice to the LORD the firstborn male of every womb, but I redeem all the firstborn of my sons.’ 16 So it shall serve as a sign on your hand and a symbol on your forehead, for with a mighty hand the LORD brought us out of Egypt.”