We certainly know that they say, ‘It is only a human that instructs him.’ The language of him to whom they refer is non-Arabic, while this is a clear Arabic language.
و هر آينه مى‌دانيم كه آنان مى‌گويند: آدميى به او مى‌آموزد زبان آن كس كه [اين قرآن را] به او نسبت مى‌دهند گنگ و نارساست و اين [قرآن‌] به زبان تازى روشن است.