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 the right, have happiness, and an excellent resting place. 29 Thus have We sent you to a community before which [other] communities have passed on so you might recite to them that which We revealed to you, while they disbelieve in the Most Merciful. Say, "He is my Lord; there is no deity except Him. Upon Him I rely, and to Him is my return." 30 If only a Koran whereby the mountains were set in motion, or the earth cleaved asunder, or the dead spoken to. No, but to Allah is the affair altogether. Do those who believe know that had Allah willed He could have guided all people? As for those who disbelieve, because of what they do, disaster will not cease to afflict them, or it alights near their home until the promise of Allah comes. Allah will not break His promise. 31