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, their hearts being at rest in God's remembrance -- in God's remembrance are at rest the hearts 28 Those who believe and work righteous works, for them is bliss and a happy resort. 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