'Freewill Offerings' in the Bible

After they arrived at the Lord’s house in Jerusalem, some of the family leaders gave freewill offerings for the house of God in order to have it rebuilt on its original site.

After that, they offered the regular burnt offering and the offerings for the beginning of each month and for all the Lord’s appointed holy occasions, as well as the freewill offerings brought to the Lord.

and all the silver and gold you receive throughout the province of Babylon, together with the freewill offerings given by the people and the priests to the house of their God in Jerusalem.