And the disbelievers said, “Why was not a sign sent down upon him from his Lord?” Proclaim, “Indeed Allah sends astray whomever He wills, and guides towards Himself the one who comes towards Him.” 27 Those who believe, their hearts being at rest in God's remembrance -- in God's remembrance are at rest the hearts 28 of those who believe and do righteous deeds; theirs is blessedness and a fair resort. 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