Deuteronomy 15:19-23

19"All the firstborn males that are born of your herd and flock you shall dedicate to the Lord your God. You shall do no work with the firstborn of your herd, nor shear the firstborn of your flock.

20You shall eat it, you and your household, before the Lord your God year by year at the place that the Lord will choose.

21But if it has any blemish, if it is lame or blind or has any serious blemish whatever, you shall not sacrifice it to the Lord your God.

22You shall eat it within your towns. The unclean and the clean alike may eat it, as though it were a gazelle or a deer.

23Only you shall not eat its blood; you shall pour it out on the ground like water.