Why Was the Qur'an Revealed Over A Period of 23 Years? Before I answer this question, let's note that if the Qur'an had been revealed all at once, people would ask: "Why was it sent down all at once and not in stages?" The ultimate answer to such questions lies with God, the All-Wise and All-Knowing. Our decisions are based on a very limited viewpoint, as we are limited creatures.