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 (in the Oneness of Allah - Islamic Monotheism), and whose hearts find rest in the remembrance of Allah, Verily, in the remembrance of Allah do hearts find rest. 28 "As for those who believe and do righteous deeds -- blissful is their end." 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 Even if there were a Quran by which mountains could be set in motion, by which the earth could be rent asunder, or by which the dead could be made to speak [they would not believe in it]. Surely all things are subject to God's will. Are the faithful unaware that, had He pleased, God could have guided all mankind? Calamity shall not cease to strike those who deny the truth because of their misdeeds or to strike near their homes, until God's promise be fulfilled. God will not fail to keep His promise. 31