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 (As for) those who believe and do good, a good final state shall be theirs and a goodly 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 And what would have happened were a Qur'an to be revealed wherewith mountains could be set in motion, or the earth cleft, or the dead made to speak? (To show such signs is not at all difficult for) everything rests entirely with Allah. So, do not the people of faith (still look forward to such a sign in response to the demand of the unbelievers and) despair as a result of knowing that had Allah so willed, He could have guided all to the Truth. Misfortune continues to afflict the unbelievers on account of their misdeeds, or to befall on locations close to their habitation. This will continue until Allah's promise (of chastisement) is fulfilled. Indeed Allah does not go back upon His promise. 31