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 For those who believe and do good works is blessedness and blessed resort' 29 Thus have We sent you to a community before which [other] communities have passed on so you might recite to them that which We revealed to you, while they disbelieve in the Most Merciful. Say, "He is my Lord; there is no deity except Him. Upon Him I rely, and to 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