'Freewill Offerings' in the Bible

Speak unto Aaron, and to his sons, and unto all the children of Israel, and say unto them, Whosoever he be of the house of Israel, or of the strangers in Israel, that will offer his offering for all his vows, and for all his freewill offerings, which they will offer unto the LORD for a burnt offering;

Besides the sabbaths of the LORD, and besides your gifts, and besides all your vows, and besides all your freewill offerings, which you give unto the LORD.

These things you shall do unto the LORD in your appointed feasts, besides your vows, and your freewill offerings, for your burnt offerings, and for your grain offerings, and for your drink offerings, and for your peace offerings.

And there you shall bring your burnt offerings, and your sacrifices, and your tithes, and heave offerings of your hand, and your vowed offerings, and your freewill offerings, and the firstlings of your herds and of your flocks:

You may not eat within your gates the tithe of your grain, or of your wine, or of your oil, or the firstlings of your herds or of your flock, nor any of your offerings which you vow, nor your freewill offerings, or heave offering of your hand:

And Kore the son of Imnah the Levite, the keeper of the east gate, was over the freewill offerings of God, to distribute the offerings to the LORD, and the most holy things.

Accept, I beseech you, the freewill offerings of my mouth, O LORD, and teach me your judgments.