Bible Verses About Offerings: Free-will

Besides the sabbaths of the Lord, and your gifts, and those things that you offer by vow, or which you shall give to the Lord voluntarily.

And thou shalt celebrate the festival of weeks to the Lord thy God, a voluntary oblation of thy hand, which thou shalt offer according to the blessing of the Lord thy God.

But that which is once gone out of thy lips, thou shalt observe, and shalt do as thou hast promised to the Lord thy God, and hast spoken with thy own will and with thy own mouth.