Those who have rejected (the message of Muhammad) say: "Why has no sign been sent down upon him from his Lord?" Tell them: "Allah lets go astray those whom He wills, and guides to Himself those who turn to Him." 27 Those who believe and find peace in their hearts from the contemplation of God: Surely there is peace of heart in the contemplation of God!" 28 (As for) those who believe and do good, a good final state shall be theirs and a goodly return. 29 Thus have We sent you (O Muhammad SAW) to a community before whom other communities have passed away, in order that you might recite unto them what We have inspired to you, while they disbelieve in the Most Beneficient (Allah) Say: "He is my Lord! La ilaha illa Huwa (none has the right to be worshipped but He)! In Him is my trust, and to Him will be my return with repentance." 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