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 believe and do the right, have happiness, and an excellent resting place. 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 cleaved asunder, or the dead spoken to. No, but to Allah is the affair altogether. Do those who believe know that had Allah willed He could have guided all people? As for those who disbelieve, because of what they do, disaster will not cease to afflict them, or it alights near their home until the promise of Allah comes. Allah will not break His promise. 31