Proverbs 27:22
Though you grind a fool in a mortar with a pestle along with grain, yet his foolishness will not be removed from him.
World English Bible (Public Domain)
In context
Before · Proverbs 27:20–21
20Sheol and Abaddon are never satisfied; and a man’s eyes are never satisfied. 21The crucible is for silver, and the furnace for gold; but man is refined by his praise.
22Though you grind a fool in a mortar with a pestle along with grain, yet his foolishness will not be removed from him.