Overall meaning : I swear by the positions of the stars in the sky—and it is surely a mighty oath, if you but knew it—that this Noble Qur’an is of tremendous benefit and goodness and is free from all defects and imperfections. It is in a well-guarded Record which only the purified angels that are from sin can touch: It is a revelation that is sent down from the Lord of all the worlds.
Would you nonetheless deny this Qur’an as a falsehood and make this return of gratitude for the provisions that Allah grants you, that you disbelieve in Him?!