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 (in the Oneness of Allah - Islamic Monotheism), and whose hearts find rest in the remembrance of Allah, Verily, in the remembrance of Allah do hearts find rest. 28 For those who believe and do good works is blessedness and blessed resort' 29 And thus We have sent you among a nation before which other nations have passed away, that you might recite to them what We have revealed to you and (still) they deny the Beneficent Allah. Say: He is my Lord, there is no god but He; on Him do I rely and to Him is my return. 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