Surat ash-Shu'ara', 178-179

If We had sent it down to a non-Arab who had then recited it to them, they still would not believe in it. (Surat ash-Shu‘ara’, 178-179 )

As a second meaning, this verse refers to Hazrat Mahdi (pbuh) also. Hazrat Mahdi (pbuh) does not know Arabic either, but teaches the Qur’an. Our Prophet (pbuh) knows Arabic very well. If we think of it as “If We had given him the task of teaching and explaining the Qur’an in the best way”, I mean as an indicative meaning, Hazrat Mahdi (pbuh) will also tell people but the ones who will not believe will not believe anyway. As a second meaning it refers to Hazrat Mahdi’s (pbuh) not knowing Arabic, yet understanding and telling the people by reading the translation of the Qur’an and commentaries and ahl al-sunnah works. Because it is clear that he will teach by reading translation of the Qur’an.