Those who deny the truth ask, "Why has no Sign been sent down to him by his Lord?" Say, "God lets go astray those whom He wills and guides to Himself those who turn to Him, 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 That is how We have sent you to a people before whom many a people have come and gone, so that you may announce to them whatever We have revealed to you. But they do not believe in Ar-Rahman. Tell them: "He is my Lord. There is no other god but He. In Him have I placed my trust, and to Him is my reversion." 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