Az-Zukhruf: (30)

(And when the truth came to them) to awaken them from the heedlessness they were in and to guide them to monotheism, (they said, "This is magic, and we are indeed disbelievers in it.")

They increased in wickedness, for they added to their polytheism the opposition of the truth and the belittling of it, so they named the Qur'an magic, disbelieved in it, and treated the Messenger of Allah (peace be upon him) with contempt.