Commentary Purg XXXII 73-84

In the scene of the transfiguration of Jesus (Matthew 17:1-8) the three apostles Peter, James, and John ascend a mountain with Jesus, see him transformed in visage (it shines with light) and raiment (his clothes become white), then see him in the company of Moses and Elijah (who, representing the law and the prophets, respectively, both promised his advent), and then hear the voice of God from a cloud proclaim that Jesus is his Son, and finally find Moses and Elijah vanished.  Just so, this simile insists, Dante thinks he finds himself (in the role of an apostle) in the company of Matelda alone.  For a study of discussions of the Transfiguration by various fathers of the Church, see Chamberas (Cham.1970.1).