From “Sermon 29” (ca. 430)
We heard when the Holy Gospel was being read of the great vision on the mount, in which Jesus showed himself to the three disciples, Peter, James, and John. “His face did shine as the sun:” this is a figure of the shining of the Gospel. “His raiment was white as the snow:” this is a figure of the purity of the Church, to which it was said by the prophet, “Though your sins be as scarlet, I will make them white as snow.”
Elijah and Moses were talking with him; because the grace of the Gospel receives witness from the Law and the Prophets. The Law is represented in Moses, the prophets in Elijah; to speak briefly. For there are the mercies of God vouchsafed through a holy martyr to be rehearsed. Let us give ear.
Peter desired three tabernacles to be made, one for Moses, one for Elijah, and one for Christ. The solitude of the mountain had charms for him; he had been wearied with the tumult of the world’s business. But why sought he three tabernacles, but because he knew not as yet the unity of the Law, and of prophecy, and of the Gospel? Lastly, he was corrected by the cloud, “While he yet spoke, behold, a bright cloud overshadowed them.” Lo, the cloud has made one tabernacle; why did you seek for three?
“And a voice came out of the cloud, This is my beloved Son, in whom I am well pleased, hear him.” Elijah speaks, but “hear him;” “Moses speaks; but “hear him.” The prophets speak, the Law speaks; but “hear Him,” who is the voice of the Law, and the tongue of the prophets. He spoke in them, and when he vouchsafed so to do, he appeared in his own person. “Hear him:” let us then hear him. When the Gospel spoke, think it was the cloud: from thence has the voice sounded out to us. Let us hear him; that is, let us do what he says, let us hope for what he has promised.
St. Augustine (354-430) was a theologian and philosopher who served as Bishop of Hippo Regius in North Africa. He was a voluminous author, whose writings about God’s grace, the Sacraments, and the Church have been profoundly influential in the development of Western Christianity. His feast day is August 26.