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 find comfort in the remembrance of God -- surely in the remembrance of God hearts can find comfort. 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 As such, We have sent you forth to a nation before whom others have passed away in order that you recite to them what We have revealed to you. Yet they disbelieve the Merciful. Say: 'He is my Lord. There is no god except 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