'Voluntary offering' in the Bible

"If his sacrifice accompanies a fulfilled vow or is a voluntary offering, it is to be eaten on the day the offeror brings the sacrifice. Anything left over is to be eaten the next day,

And if any present a sacrifice of peace-offering to Jehovah to accomplish a vow, or a voluntary offering of oxen or small cattle, it shall be without blemish to be accepted: there shall be no defect therein.

A bullock and a sheep that hath a member too long or too short, that mayest thou offer as a voluntary offering; but as a vow it shall not be accepted.