'Refine' in the Bible

Then I will bring the remaining third into the fire; I will refine them like silver is refined and will test them like gold is tested. They will call on my name and I will answer; I will say, 'These are my people,' and they will say, 'The Lord is my God.'"

He will act like a refiner and purifier of silver and will cleanse the Levites and refine them like gold and silver. Then they will offer the Lord a proper offering.