Strong H5071 נְדָבָה nedâbâh · voluntariness

Ezra

1. Ezra 1:4
   And whosoever remaineth in any place where he sojourneth, let the men of his place help him with silver, and with gold, and with goods, and with beasts, beside the freewill offering for the house of God that is in Jerusalem.
2. Ezra 3:5
   And afterward offered the continual burnt offering, both of the new moons, and of all the set feasts of the Lord that were consecrated, and of every one that willingly offered a freewill offering unto the Lord.
3. Ezra 8:28
   And I said unto them, Ye are holy unto the Lord; the vessels are holy also; and the silver and the gold are a freewill offering unto the Lord God of your fathers.