Proverbs 27:21-22

²¹As silver is tried in the fining-pot and gold in the furnace: so a man is tried by the mouth of him that praiseth. The heart of the wicked seeketh after evils, but the righteous heart seeketh after knowledge.

²²Though thou shouldst bray a fool in the mortar, as when a pestle striketh upon sodden barley, his folly would not be taken from him.