Hisham bin Muslim Qurashi said: I was with Ibn Muhairiz in the valley of Marj al-Deebaj. Finding him alone, I asked him about an issue. He said: Why do you ask about issues? I said: If there were no issues, knowledge would vanish. He replied: Do not say that knowledge would vanish. As long as the Noble Qur'an is recited, knowledge will not vanish. Yes, you may say that understanding and comprehension will be taken away.