Exodus 13:13-15

Young's Literal Translation

¹³ `And every firstling of an ass thou dost ransom with a lamb, and if thou dost not ransom [it], then thou hast beheaded it: and every first-born of man among thy sons thou dost ransom.

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;