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 whose hearts are set at rest by the remembrance of Allah; now surely by Allah's remembrance are the hearts set at rest. 28 Those who believe and do right: Joy is for them, and bliss (their) journey's end. 29 Thus have we sent thee amongst a People before whom (long since) have (other) Peoples (gone and) passed away; in order that thou mightest rehearse unto them what We send down unto thee by inspiration; yet do they reject (Him), the Most Gracious! Say: "He is my Lord! There is no god but He! On Him is my trust, and to Him do I turn!" 30 Yet even if [they should listen to] a [divine] discourse by which mountains could be moved, or the earth cleft asunder, or the dead made to speak - [they who are bent on denying the truth would still refuse to believe in it]! Nay, but God alone has the power to decide what shall be. Have, then, they who have attained to faith not yet come to know that, had God so willed; He would indeed have guided all mankind aright? But as for those who are bent on denying the truth - in result of their [evil] deeds, sudden calamities will always befall them or will alight close to their homes; [and this will continue] until God's promise [of resurrection] is fulfilled: verily, God never fails to fulfil His promise! 31