Obstinance of the Chiefs of the Quraysh

Allah tells us about the obstinance of the disbelievers of the Quraysh, who were opposed to the message and denied Allah. When the Messenger ﷺ read to them from the Book of Allah and His clear evidence they said to him: "Bring a Qur'an other than this." They wanted the Prophet to take back this Book and bring them another book of a different style or change it to a different form. So Allah said to His Prophet :

قُلْ مَا يَكُونُ لِى أَنْ أُبَدِّلَهُ مِن تِلْقَآءِ نَفْسِى

The last verse (17) emphasizes the subject conclusively by warning that attributing any statement to Allah Ta` ala that was not His Word, or denying what actually was, were crimes deserving severe punishment.