3. And, lo, there appeared to them Moses and Elijah. It is asked, Were Moses and Elijah actually present? or was it only an apparition that was exhibited to the disciples, as the prophets frequently beheld visions of things that were absent? Though the subject admits, as we say, of arguments on both sides, yet I think it more probable that they were actually brought to that place. There is no absurdity in this supposition; for God has bodies and souls in his hand, and can restore the dead to life at his pleasure, whenever he sees it to be necessary. Moses and Elijah did not then rise on their own account, (478) but in order to wait upon Christ. It will next be asked, How came the apostles to know Moses and Elijah, whom they had never seen? The answer is easy. God, who brought them forward, gave also signs and tokens by which they were enabled to know them. It was thus by an extraordinary revelation that they obtained the certain knowledge that they were Moses and Elijah
But why did these two appear rather than others who equally belonged to the company of the holy fathers? It was intended to demonstrate that Christ alone is the end of the Law and of the Prophets; and that single reason ought to satisfy us: for it was of the utmost importance to our faith that Christ did not come into our world without a testimony, but with commendations which God had formerly bestowed. I have no objection, however, to the reason which is commonly adduced, that Elijah was selected, in preference to others, as the representative of all the Prophets; because, though he left nothing in writing, yet next to Moses he was the most distinguished of their number, restored the worship of God which had been corrupted, and stood unrivaled in his exertions for vindicating the Law and true godliness, which was at that time almost extinct.
And they conversed with Jesus. When they appeared along with Christ, and held conversation with him, this was a declaration of their being agreed. The subject on which they conversed is stated by Luke only: they talked of the decease which awaited Christ at Jerusalem This must not be understood to refer to them as private individuals, but rather to the commission which they had formerly received. Though it was now a long time since they had died and finished the course of their calling, yet our Lord intended once more to ratify by their voice what they had taught during their life, in order to inform us that the same salvation, through the sacrifice of Christ, is held out to us in common with the holy fathers. At the time when the ancient prophets uttered their predictions concerning the death of Christ, he himself, who was the eternal wisdom of God, was sitting on the invisible throne of his glory. Hence it follows that, when he was clothed in flesh, he was not liable to death any farther than as he submitted to it of his own free will.
(478) “ Moise et Elie ne sont pas lors ressuscitez pour eux, et pour le regard de la resurrection derniere;” — “Moses and Elijah did not then rise for themselves, and with respect to the last resurrection.”