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 whose hearts are set at rest by the remembrance of Allah; now surely by Allah's remembrance are the hearts set at rest. 28 So those who believe (in the message of the Truth) and do good are destined for happiness and a blissful end. 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 And even if there were a Quran with which the mountains were made to pass away, or the earth were travelled over with it, or the dead were made to speak thereby; nay! the commandment is wholly Allah's, Have not yet those who believe known that if Allah please He would certainly guide all the people? And (as for) those who disbelieve, there will not cease to afflict them because of what they do a repelling calamity, or it will alight close by their abodes, until the promise of Allah comes about; surely Allah will not fail in (His) promise. 31