The unbelievers say, "Why have not some miracles been sent to him, (Muhammad), from his Lord." Say, "God causes whomever He wants to go astray and He guides those who turn to Him in repentance 27 and the faithful ones whose hearts are comforted by the remembrance of God. Remembrance of God certainly brings comfort to all hearts. 28 So those who believe (in the message of the Truth) and do good are destined for happiness and a blissful end. 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