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 and do the right, have happiness, and an excellent resting place. 29 That is how We have sent you to a people before whom many a people have come and gone, so that you may announce to them whatever We have revealed to you. But they do not believe in Ar-Rahman. Tell them: "He is my Lord. There is no other god but He. In Him have I placed my trust, and to Him is my reversion." 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