Deuteronomy 15:19-23

19All the firstling males that are born of thy herd and of thy flock thou shalt sanctify unto the LORD thy God: thou shalt do no work with the firstling of thine ox, nor shear the firstling of thy flock. 20Thou shalt eat it before the LORD thy God year by year in the place which the LORD shall choose, thou and thy household. 21And if it have any blemish, as if it be lame or blind, any ill blemish whatsoever, thou shalt not sacrifice it unto the LORD thy God. 22Thou shalt eat it within thy gates: the unclean and the clean shall eat it alike, as the gazelle, and as the hart. 23Only thou shalt not eat the blood thereof; thou shalt pour it out upon the ground as water.