The Venerable John Climacus is the author of The Ladder of Divine Ascent. John came to Mount Sinai as a sixteen-year-old youth and remained there, first as a novice, later as a recluse, and finally as abbot of Sinai until his eightieth year, when he reposed, in about the year 649. His biographer, the monk Daniel, says about him: “His body ascended the heights of Sinai, while his soul ascended the heights of heaven.” He remained under obedience to his spiritual father, Martyrius, for nineteen years. Anastasius of Sinai, seeing the young John, prophesied that he would become the abbot of Sinai. After the death of his spiritual father, John withdrew into a cave, where he lived a life of strict asceticism for twenty years. His disciple, Moses, fell asleep one day under the shade of a large stone. John, at prayer in his cell, saw that his disciple was in danger and prayed to God for him. Later, when Moses returned, he fell on his knees and gave thanks to his spiritual father for saving him from certain death. He related that in a dream he had heard John calling him, and that he had jumped up at the moment the stone had fallen. Had he not jumped, the stone would have crushed him.