And those who disbelieved say, "Why has a sign not been sent down to him from his Lord?" Say, [O Muhammad], "Indeed, Allah leaves astray whom He wills and guides to Himself whoever turns back [to Him] - 27 Those who believe and whose hearts are set at rest by the remembrance of Allah; now surely by Allah's remembrance are the hearts set at rest. 28 of those who believe and do righteous deeds; theirs is blessedness and a fair resort. 29 Thus We have sent thee unto a community before whom other communities have passed away, in order that thou mayest recite unto them that which We have revealed unto thee; yet they disbelieve in the Compassionate. Say thou: He is my Lord, there is no god but he; on Him I rely, and unto Him is my return in penitence. 30 And if there were a Qur'an whereby the mountains could be moved or whereby the earth could be traversed or whereby the dead could be spoken to, it would be in vain. Aye! the affair belongeth to Allah entirely. Have not then those who believe yet known? that had Allah willed, He would have guided all mankind! And a rattling adversity ceaseth not to befall those who disbelieve for that which they have wrought or to alight nigh unto their habitation until Allah's promise cometh; verily Allah faileth not the tryst. 31