It is said that when a foolish man is instructed in something very nice, he generally cannot accept it. Indeed, he actually becomes angry. Such anger is compared to the poison of a serpent, for when a serpent is fed milk and bananas, its poison actually increases. Instead of becoming merciful or sober, the serpent increases its poisonous venom when fed nice foodstuffs. Similarly, when a fool is instructed, he does not rectify himself, but actually becomes angry.