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 Such are the ones who believe (in the message of the Prophet) and whose hearts find rest in the remembrance of Allah. Surely in Allah's remembrance do hearts find rest. 28 [and so it is that] they who attain to faith and do righteous deeds are destined for happiness [in this world] and the most beauteous of all goals [in the life to come]!" 29 Thus have we sent thee amongst a People before whom (long since) have (other) Peoples (gone and) passed away; in order that thou mightest rehearse unto them what We send down unto thee by inspiration; yet do they reject (Him), the Most Gracious! Say: "He is my Lord! There is no god but He! On Him is my trust, and to Him do I turn!" 30 If only a Koran whereby the mountains were set in motion, or the earth were cleft, or the dead were spoken to -- nay, but God's is the affair altogether. Did not the believers know that, if God had willed, He would have guided men all together? And still the unbelievers are smitten by a shattering for what they wrought, or it alights nigh their habitation, until God's promise comes; and God will not fail the tryst. 31