Leviticus 27:25-29

And all thy estimations shall be according to the shekel of the sanctuary: twenty gerahs shall be the shekel.

Only the firstling of the beasts, which should be the LORD’s firstling, no man shall sanctify it; whether it be ox, or sheep: it is the LORD’s.

And if it be of an unclean beast, then he shall redeem it according to thine estimation, and shall add a fifth part of it thereto: or if it be not redeemed, then it shall be sold according to thy estimation.

Notwithstanding no devoted thing, that a man shall devote unto 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 unto the LORD.

None devoted, which shall be devoted of men, shall be redeemed; but shall surely be put to death.