Leviticus 22:18

22:18 “Speak to Aaron, his sons, and all the Israelites and tell them, ‘When any man from the house of Israel or from the foreigners in Israel presents his offering for any of the votive or freewill offerings which they present to the Lord as a burnt offering,

Leviticus 22:21

22:21 If a man presents a peace offering sacrifice to the Lord for a special votive offering or for a freewill offering from the herd or the flock, it must be flawless to be acceptable; it must have no flaw.