Redeem the firstborn

15Every firstborn that opens the womb, of all flesh that they present to Yahweh, whether man or beast, shall be yours. Nevertheless, you must surely redeem the firstborn of man, and you must redeem the firstborn of the unclean beast.

16And those to be redeemed from a month old, you shall redeem according to your valuation: five shekels of silver, by the sanctuary shekel; it is twenty gerahs.