'Freewill Offerings' in the Bible

When [some] of the heads of {families} came to the house of Yahweh that [is] in Jerusalem, they gave freewill offerings for the house of God to erect it on its place.

and all of the silver and gold that you will find in the whole province of Babylonia, with the freewill offerings of the people and the priests giving willingly for the house of their God in Jerusalem.