And those who disbelieve say: "Why is not a sign sent down to him (Muhammad SAW) from his Lord?" Say: "Verily, Allah sends astray whom He wills and guides unto Himself those who turn to Him in repentance." 27 They are those who believe and whose hearts find rest in the remembrance of Allah. Lo! in the remembrance of Allah hearts do find rest. 28 For those who believe and do good works is blessedness and blessed resort' 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 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