Leviticus 27:26-29

26Only the firstling of the beasts, which should be the LORD’S firstling, no man shall sanctify it; whether ox, or sheep: it is the LORD’S.1 27And if it shall be of an unclean beast, then he shall redeem it according to thy estimation, and shall add to it a fifth part of it: or if it shall be not redeemed, then it shall be sold according to thy estimation. 28However no devoted thing, that a man shall devote to the LORD of all that he hath, both of man and beast, and of the field of his possession, shall be sold or redeemed: every devoted thing is most holy to the LORD. 29None devoted, which shall be devoted by men, shall be redeemed; but shall surely be put to death.