Catena Aurea, 2nd Weekend of Lent (B), Mk 9:2-10
Theophylact (1055-1107): Again, mystically; after the end of this world, which was made in six days, Jesus will take us up (if we be His disciples) into a high mountain, that is, into heaven, where we shall see His exceeding glory.
St. John Chrysostom (c. 347-407): Hom. in Matt., 56: He brings Moses and Elijah before them; first, indeed, because the multitudes said that Christ was Elijah, and one of the Prophets. He shows Himself to the Apostles with them, that they might see the difference between the Lord and His servants. And again because the Jews accused Christ of transgressing the law, and thought Him a blasphemer, as if He arrogated to Himself the glory of His Father, He brought before them those who shone conspicuous in both ways; for Moses gave the Law, and Elijah was zealous for the glory of God; for which reason neither would have stood near Him, if He had been opposed to God and to His law. And that they might know that He holds the power of life and of death, He brings before them both Moses who was dead, and Elijah who had not yet suffered death. Furthermore He signified by this that the doctrine of the Prophets was the schoolmaster to the doctrine of Christ (Gal 4:2)1. He also signified the junction of the New and Old Testament, and that the Apostles shall be joined in the resurrection with the Prophets, and both together shall go forth to meet their common King.
The Venerable Bede (672/3-735): If the transfigured humanity of Christ and the society of but two saints seen for a moment, could confer delight to such a degree that Peter would, even by serving them, delay their departure, how great a happiness will it be to enjoy the vision of Divinity amidst choirs of Angels forever?
Now because Peter sought for a material tent, he was covered with the shadow of the cloud, that he might learn that in the resurrection they are to be protected not by the covering of houses, but by the glory of the Holy Spirit.
Wherefore it goes on, “There was a cloud that overshadowed them.” And the reason why they obtained no answer from the Lord was that they asked unadvisedly; but the Father answered for the Son. Wherefore there follows, “And a voice came out of the cloud, saying, This is My beloved Son, in whom I am well pleased.”
And we must observe, that, as when the Lord was baptized in Jordan, so on the mountain, covered with brightness, the whole mystery of the Holy Trinity is declared. . . Nor is it without reason that the Holy Spirit appeared here in a bright cloud, there in the form of a dove; because he who now with a simple heart keeps the faith which he has embraced, shall then contemplate what he had believed with the brightness of open vision.
1 Galatians 4:1-5 I mean that the heir, as long as he is a child, is no better than a slave, though he is the owner of all the estate; 2 but he is under guardians and trustees until the date set by the father. 3 So with us; when we were children, we were slaves to the elemental spirits of the universe. 4 But when the time had fully come, God sent forth his Son, born of woman, born under the law, 5 to redeem those who were under the law, so that we might receive adoption as sons.