The unbelievers say, "Why have not some miracles been sent to him, (Muhammad), from his Lord." Say, "God causes whomever He wants to go astray and He guides those who turn 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 Those who believe and do right: Joy is for them, and bliss (their) journey's end. 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