Those who have rejected (the message of Muhammad) say: "Why has no sign been sent down upon him from his Lord?" Tell them: "Allah lets go astray those whom He wills, and guides to Himself those who turn to 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 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 had been a Quran with which mountains could be moved (from their places), or the earth could be cloven asunder, or the dead could be made to speak (it would not have been other than this Quran). But the decision of all things is certainly with Allah. Have not then those who believe yet known that had Allah willed, He could have guided all mankind? And a disaster will not cease to strike those who disbelieve because of their (evil) deeds or it (i.e. the disaster) settle close to their homes, until the Promise of Allah comes to pass. Certainly, Allah does not fail in His Promise. 31