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, their hearts being at rest in God's remembrance -- in God's remembrance are at rest the hearts 28 "For those who believe and work righteousness, is (every) blessedness, and a beautiful place of (final) return." 29 Thus have We sent you as a Messenger to a community before which many other communities have passed away that you may recite to them whatever We have revealed to you. And yet they deny the Lord of Mercy. Say to them: "He is my Lord, there is no god but Him. In Him I have placed all my trust and to Him I shall return." 30 Had it been possible for a Lecture to cause the mountains to move, or the earth to be torn asunder, or the dead to speak, (this Qur'an would have done so). Nay, but Allah's is the whole command. Do not those who believe know that, had Allah willed, He could have guided all mankind? As for those who disbelieve, disaster ceaseth not to strike them because of what they do, or it dwelleth near their home until the threat of Allah come to pass. Lo! Allah faileth not to keep the tryst. 31