Deuteronomy 15:19-23

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