Leviticus 22:18; Leviticus 22:21

18 "Speak to Aaron and his sons and all the people of Israel and say to them, When any one of the house of Israel or of the sojourners in Israel presents a burnt offering as his offering, for any of their vows or freewill offerings that they offer to the LORD,

21 And when anyone offers a sacrifice of peace offerings to the LORD to fulfill a vow or as a freewill offering from the herd or from the flock, to be accepted it must be perfect; there shall be no blemish in it.