The unbelievers say: "How is it that no miracle was sent down to him by his Lord?" Say: "God leads whosoever He wills astray, and guides whoever turns to Him in repentance. 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 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