'Free will offerings' in the Bible

and they received of Moses all the offering which the children of Israel had brought for the work of the service of the sanctuary, wherewith to make it. And they brought yet unto him freewill-offerings every morning.

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 sojourners in Israel, that offereth his oblation, whether it be any of their vows, or any of their freewill-offerings, which they offer unto Jehovah for a burnt-offering;

besides the sabbaths o Jehovah, and besides your gifts, and besides all your vows, and besides all your freewill-offerings, which ye give unto Jehovah.

These ye shall offer unto Jehovah in your set feasts, besides your vows, and your freewill-offerings, for your burnt-offerings, and for your meal-offerings, and for your drink-offerings, and for your peace-offerings.

and thither ye shall bring your burnt-offerings, and your sacrifices, and your tithes, and the heave-offering of your hand, and your vows, and your freewill-offerings, and the firstlings of your herd and of your flock:

Thou mayest not eat within thy gates the tithe of thy grain, or of thy new wine, or of thine oil, or the firstlings of thy herd or of thy flock, nor any of thy vows which thou vowest, nor thy freewill-offerings, nor the heave-offering of thy hand;

And Kore the son of Imnah the Levite, the porter at the east gate , was over the freewill-offerings of God, to distribute the oblations of Jehovah, and the most holy things.

Free-will-offerings of my mouth, Accept, I pray Thee, O Jehovah, And Thy judgments teach Thou me.

and offer a sacrifice of thanksgiving of that which is leavened, and proclaim freewill-offerings and publish them: for this pleaseth you, O ye children of Israel, saith the Lord Jehovah.