Proverbs 27:17-22

As iron sharpens iron, so one person sharpens another. The one who guards a fig tree will eat its fruit, and whoever protects their master will be honored. As water reflects the face, so one’s life reflects the heart. Death and Destruction are never satisfied, and neither are human eyes. The crucible for silver and the furnace for gold, but people are tested by their praise. Though you grind a fool in a mortar, grinding them like grain with a pestle, you will not remove their folly from them.