Overall meaning : Therefore, remind people, Muhammad, with the Qur’an. By the grace of your Lord, you are neither a soothsayer nor a madman, as they falsely claim!
Or do the Quraysh idolaters say, ‘Muhammad is but a poet; let us await whatever calamity time will bring upon him!’ Say to them, ‘Wait for my ruin if you will. I, too, am waiting for Allah’s punishment to descend upon you.’ Is it their reason that directs them to utter such falsehoods? Rather, they are arrogant people who have exceeded all Allah’s bounds! Or do they say, ‘Muhammad has fabricated the Qur’an himself and has falsely ascribed it to Allah’?! By no means! Rather, they arrogantly refuse to believe the truth that has come to them form Allah! Let them, then, produce a scripture like this Qur’an if what they say is true.
Were they created without there being a Creator to create them, or were they their own creators? Did they create the heavens and the earth? No. In truth they have no firm belief!