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 Who have believed and whose hearts have rest in the remembrance of Allah. Verily in the remembrance of Allah do hearts find rest! 28 Those who believe (in the Oneness of Allah - Islamic Monotheism), and work righteousness, Tuba (it means all kinds of happiness or name of a tree in Paradise) is for them and a beautiful place of (final) return. 29 Thus We have sent thee among a nation before which other nations have passed away, to recite to them that We have revealed to thee; and yet they disbelieve in the All-merciful. Say: 'He is my Lord -- there is no god but He. In Him I have put my trust, and to Him I turn.' 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