Deuteronomy 15:19-22

MSB(i) 19 You must set apart to the LORD your God every firstborn male produced by your herds and flocks. You are not to put the firstborn of your oxen to work, nor are you to shear the firstborn of your flock. 20 Each year you and your household are to eat it before the LORD your God in the place the LORD will choose. 21 But if an animal has a defect, is lame or blind, or has any serious flaw, you must not sacrifice it to the LORD your God. 22 Eat it within your gates; both the ceremonially unclean and clean may eat it as they would a gazelle or a deer.