And those who disbelieved say, "Why has a sign not been sent down to him from his Lord?" Say, [O Muhammad], "Indeed, Allah leaves astray whom He wills and guides to Himself whoever turns back [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 Those who have believed and done righteous deeds - a good state is theirs and a good return. 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 If there were a Qur'an with which mountains were moved, or the earth were cloven asunder, or the dead were made to speak, (this would be the one!) But, truly, the command is with Allah in all things! Do not the Believers know, that, had Allah (so) willed, He could have guided all mankind (to the right)? But the Unbelievers,- never will disaster cease to seize them for their (ill) deeds, or to settle close to their homes, until the promise of Allah come to pass, for, verily, Allah will not fail in His promise. 31