'Free will' in the Bible

and will make an offering by fire to Jehovah, a burnt offering or a sacrifice in performing a vow, or in a free-will offering, or in your solemn feasts, to make a sweet savor to Jehovah, from the herd or from the flock,

You shall prepare these to Jehovah in your appointed seasons, besides your vows and your free-will offerings, for your burnt offerings, and for your food offerings, and for your drink offerings, and for your peace offerings.