And those who disbelieved say, "Why has a sign not been sent down to him from his Lord?" Say, [O Muhammad], "Indeed, Allah leaves astray whom He wills and guides to Himself whoever turns back [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 Those who believe and work righteous works, for them is bliss and a happy resort. 29 We have sent you to a nation before whom there lived many nations so that you would read to them what We have revealed to you. They still deny the existence of the Beneficent God. Say, "He is my Lord besides whom there is no other God. I trust Him and turn to Him in repentance." 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