[15] Every thing that openeth the matrix in all flesh, which they bring unto the LORD, whether it be of men or beasts, shall be thine: nevertheless the firstborn of man shalt thou surely and the firstling of unclean beasts shalt thou redeem. [16] And those that are to be redeemed from a month old shalt thou redeem, according to thine estimation, for the money of five shekels, of the sanctuary, which is twenty gerahs. [17] But the firstling of a cow, or the firstling of a sheep, or the firstling of a goat, thou shalt not redeem; they are holy: thou shalt sprinkle their blood upon the altar, and shalt burn their fat for an offering made by fire, for a sweet savour unto the LORD.