'Free will' in the Bible

Kore the son of Imnah the Levite, the porter at the east [gate], was over the freewill offerings of God, to distribute the offerings of Yahweh, and the most holy things.

His princes gave for a freewill offering to the people, to the priests, and to the Levites. Hilkiah and Zechariah and Jehiel, the rulers of the house of God, gave to the priests for the Passover offerings two thousand and six hundred [small livestock], and three hundred head of cattle.