Al-Furqan · 25:4

4. And those who disbelieved in Allah and His Messenger said: “This Qur’ān is nothing but a lie which Muhammad has fabricated and blasphemously attributed to Allah. Other people have also helped him in its fabrication”. These disbelievers themselves have made a false statement, because the Qur’ān is the speech of Allah; it is impossible for humans and jinn to come up anything like it.