The unbelievers say, "Why have not some miracles been sent to him, (Muhammad), from his Lord." Say, "God causes whomever He wants to go astray and He guides those who turn to Him in repentance 27 Such are the ones who believe (in the message of the Prophet) and whose hearts find rest in the remembrance of Allah. Surely in Allah's remembrance do hearts find rest. 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