NOW THOSE who are bent on denying the truth [of the Prophet's message] say: "Why has no miraculous sign ever been bestowed upon him from on high by his Sustainer?" Say: "Behold, God lets go astray him who wills [to go astray,] just as He guides unto Himself all who turn unto Him 27 Those who believe (in the Oneness of Allah - Islamic Monotheism), and whose hearts find rest in the remembrance of Allah, Verily, in the remembrance of Allah do hearts find rest. 28 "For those who believe and work righteousness, is (every) blessedness, and a beautiful place of (final) return." 29 Thus have We sent you to a community before which [other] communities have passed on so you might recite to them that which We revealed to you, while they disbelieve in the Most Merciful. Say, "He is my Lord; there is no deity except Him. Upon Him I rely, and to Him is my 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