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 their rest in the remembrance of God - for, verily, in the remembrance of God [men's] hearts do find their rest: 28 Those who believe and do the right, have happiness, and an excellent resting place. 29 Thus We have sent you to a people, before whom other peoples have passed away, so that you may recite to them what We have revealed to you. Yet they deny the Gracious God. Say, "He is my Lord; there is no god but He. In Him I put my trust and to Him I shall 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