And if there were a Quran by which the mountains were moved, or by which the earth was torn asunder, or the dead made to speak (this would be the one, but what would be the point) - Nay, Allah's is the whole command! Did not those who believe know that if Allah had pleased He would have guided all mankind? As for those who disbelieve calamity (disaster) does not cease to overtake them for what they do, or it dwells close by their homes until Allah's promise comes to pass. Verily, Allah fails not in His promise.