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 Those who have believed and done righteous deeds - a good state is theirs and a good return. 29 We have sent you to a nation before whom there lived many nations so that you would read to them what We have revealed to you. They still deny the existence of the Beneficent God. Say, "He is my Lord besides whom there is no other God. I trust Him and turn to Him in repentance." 30 If only a Koran whereby the mountains were set in motion, or the earth were cleft, or the dead were spoken to -- nay, but God's is the affair altogether. Did not the believers know that, if God had willed, He would have guided men all together? And still the unbelievers are smitten by a shattering for what they wrought, or it alights nigh their habitation, until God's promise comes; and God will not fail the tryst. 31