Those who have rejected (the message of Muhammad) say: "Why has no sign been sent down upon him from his Lord?" Tell them: "Allah lets go astray those whom He wills, and guides to Himself those who turn to Him." 27 Those who believe (in the Oneness of Allah - Islamic Monotheism), and whose hearts find rest in the remembrance of Allah, Verily, in the remembrance of Allah do hearts find rest. 28 Those who believe and do right: Joy is for them, and bliss (their) journey's end. 29 Similarly We sent you (O dear Prophet Mohammed – peace and blessings be upon him) towards the nation, before whom other nations have passed away, for you to recite to them the divine revelations We sent down to you, whereas they are denying the Most Gracious; proclaim, “He is my Lord – there is no worship except for Him; I rely only upon Him and only towards Him is my return.” 30 And if there was any qur'an by which the mountains would be removed or the earth would be broken apart or the dead would be made to speak, [it would be this Qur'an], but to Allah belongs the affair entirely. Then have those who believed not accepted that had Allah willed, He would have guided the people, all of them? And those who disbelieve do not cease to be struck, for what they have done, by calamity - or it will descend near their home - until there comes the promise of Allah. Indeed, Allah does not fail in [His] promise. 31