السكوت على الأحمق أفضل جوابه
Not talking to a bigot is the best answer to him.
“Bigot” in this quote means: someone who refuses to understand, although he has the ability to understand. It can also be replaced with “Zealot” or “Fanatic”.
Although you can defeat such a person in a debate, he will not admit it. And he will continue debating. Therefore, the best answer to his verbal attack is to be silent. That way, you don’t waste your energy or time.
Note that the literal translation of “أحمق” into English is “Fool”. But as I understand it, the Imam meant by that word “Bigot”, not “Fool”.