'Free will' in the Bible
“If the sacrifice he offers is a vow or a freewill offering, it is to be eaten on the day he presents his sacrifice, and what is left over may be eaten on the next day.
“Speak to Aaron, his sons, and all the Israelites and tell them: Any man of the house of Israel or of the foreign residents in Israel who presents his offering—whether they present freewill gifts or payment of vows to the Lord as burnt offerings—
“When a man presents a fellowship sacrifice to the Lord to fulfill a vow or as a freewill offering from the herd or flock, it has to be unblemished to be acceptable; there must be no defect in it.
You may sacrifice as a freewill offering any animal from the herd or flock that has an elongated or stunted limb, but it is not acceptable as a vow offering.
These are in addition to the offerings for the Lord’s Sabbaths, your gifts, all your vow offerings, and all your freewill offerings that you give to the Lord.