How do we discuss with someone who believes that "recitation" in the verse ("And you did not recite any book before it, nor did you inscribe it with your right hand") refers specifically to revealed scriptures, and does not mean that the Prophet, may God's prayers and peace be upon him, was entirely illiterate?

Allah described His Messenger, peace and blessings be upon him, as unlettered (ummi) in more than one place in His Book, such as His saying, the Most High: "Those who follow the Messenger, the unlettered prophet." His unletteredness is not a deficiency but rather proof that the guidance he conveyed was from his Lord and not from books or philosophies of his era. No attribution has been found to Al-Raghib Al-Isfahani claiming that the verse in Surah Al-Ankabut only negates the recitation of revealed scriptures and does not indicate his unletteredness, in his book "Mufradat Gharib Al-Qur'an." And whoever disputes his unletteredness, peace and blessings be upon him, at the time of revelation, is refuted by the evidence.