Those who deny the truth ask, "Why has no Sign been sent down to him by his Lord?" Say, "God lets go astray those whom He wills and guides to Himself those who turn to Him, 27 and the faithful ones whose hearts are comforted by the remembrance of God. Remembrance of God certainly brings comfort to all hearts. 28 For those who believe and do good works is blessedness and blessed resort' 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 there been a Qur'an which could have made the mountains move, or the earth to cleave asunder, or the dead to speak, yet all authority belongs to God. Have the believers not learnt that if God had so willed He could have guided all mankind? As for unbelievers, they will be visited by misfortune endlessly for what they have done; or it would sit in their homes till the promised threat of God comes to pass. Surely God does not go back on His promise. 31