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 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 Those who believe and do right: Joy is for them, and bliss (their) journey's end. 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 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