Proverbs Chapter 17, Verse 3

3: The fining pot is for silver, and the furnace for gold: but the LORD trieth the hearts.— edit KJV text
3: As silver is tried by fire, and gold in the furnace: so the Lord trieth the hearts.— edit Douay text
3: As silver and gold are tried in a furnace, so are choice hearts with the Lord.— edit LXX text