Some way up the steep side of Mount Hira is a cave to which Mohammed often retired for solitary meditation, and sometimes Khadijah, his wife, would accompany him to this quiet retreat. For Mohammed was passing through a time of doubt and perplexity; He longed for the Truth, which he felt was not to be found in the worship of idols, but, as yet, the way was not clear to his mind. We must remember that Mohammed was never in a position to learn all that our religion has taught us; he may, from time to time, have met with a few Christians, but the Christianity that found its way into Arabia in those days had lost much of its purity. Nevertheless, when he had firmly grasped the idea that "God is One, the Eternal," that "there is none like unto Him," Mohammed had got far on the way leading to Truth. The Unity of God is the one great outstanding doctrine of the Mohammedan faith. That he should have been chosen to preach this doctrine to mankind dawned by slow degrees on Mohammed's mind. This is how it came about. It was the month of Ramadan, and Mohammed had gone to the cave on Mount Hira, to devote this time to prayer and fasting. Unusually excited by his thoughts, he fell into a trance and saw a vision. On the far horizon he beheld the form of the Archangel Gabriel—nearer and nearer he approached until he stood within two bows' lengths of Mohammed. Holding out a scroll, the Angel commanded him to "Read!" "But I cannot read," said Mohammed, trembling before the heavenly vision. Three times the Angel cried "Read!" and then he recited the words that were written on the scroll, proclaiming the greatness of God, the Creator of mankind...