Exodus 13:14-16 Young's Literal Translation (YLT)
14 `And it hath been, when thy son asketh thee hereafter, saying, What [is] this? that thou hast said unto him, By strength of hand hath Jehovah brought us out from Egypt, from a house of servants;
15 yea, it cometh to pass, when Pharaoh hath been pained to send us away, that Jehovah doth slay every first-born in the land of Egypt, from the first-born of man even unto the first-born of beast; therefore I am sacrificing to Jehovah all opening a womb who [are] males, and every first-born of my sons I ransom;
16 and it hath been for a token on thy hand, and for frontlets between thine eyes, for by strength of hand hath Jehovah brought us out of Egypt.'