'Freewill Offerings' in the Bible

In any place where a survivor (Jewish exile) may live, let the men (Gentiles) of that place support him with silver and gold, with goods and cattle, together with freewill offerings for the house of God in Jerusalem.’”

Some of the heads of the fathers’ households (extended families), when they arrived at the house of the Lord in Jerusalem, made voluntary contributions for the house of God to rebuild it on its [old] foundation.

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 which you find in the whole province of Babylon, along with the freewill offering of the people and of the priests for the house of their God in Jerusalem.