The Coming of Elijah
And as they were coming down the mountain, he charged them to tell no one what they had seen, until the Son of man should have risen from the dead. So they kept the matter to themselves, questioning what the rising from the dead meant. And they asked him, “Why do the scribes say that first Eli'jah must come?” And he said to them, “Eli'jah does come first to restore all things; and how is it written of the Son of man, that he should suffer many things and be treated with contempt? But I tell you that Eli'jah has come, and they did to him whatever they pleased, as it is written of him.”
Origen, in Matt. tom. 12, 43 - After the shewing of the mystery on the mount, the Lord commanded His disciples, as they were coming down from the mount, not to reveal His transfiguration, before the glory of His Passion and Resurrection.Wherefore it is said, "And as they came down from the mountain, He charged them that they should tell no man what things they had seen, till the Son of man were risen from the dead."
Chrys., Hom. in Matt., 56 - Where He not only orders them to be silent, but mentioning His Passion, He implies the cause why they were to be silent.
Theophylact - Which He did lest men should be offended, hearing such glorious things of Him Whom they were about to see crucified. It was not therefore fitting to say such things of Christ before He suffered, but after His resurrection they were likely to be believed.
Pseudo-Chrys., Vict. Ant. e Cat. in Marc. - But they, being ignorant of the mystery of the resurrection, took hold of that saying, and disputed one with another.
Wherefore there follows, "And they kept that saying with themselves, questioning one with another what the rising from the dead should mean."
Pseudo-Jerome - This, which is peculiar to Mark, means, that when death shall have been swallowed up in victory, we shall have no memory for the former things.
It goes on, "And they asked Him, saying, "Why say the Scribes that Elias must first come?"
Chrys. - The design of the disciples in asking this question seems to me to be this. We indeed have seen Elias with Thee, and have seen Thee before seeing Elias, but the Scribes say that Elias cometh first; we therefore believe that they have lied.
Bede - Or thus; the disciples thought that the change which they had seen in Him in the mount, was His transformation to glory; and they say, If Thou hast already come in glory, wherefore doth not Thy forerunner appear? chiefly because they had seen Elias go away.
Chrys., Hom. in Matt. 57 - But what Christ answered to this, is seen by what follows, "And He answered and told them, Elias verily cometh first, and restoreth all things;" in which He shews that Elias will come before His second advent. For the Scriptures declare two advents of Christ, namely, one which has taken place, and another which is to come; but the Lord asserts that Elias is the forerunner of the second advent.
Bede - Again, He will restore all things, that is to say, those things which Malachi points out, saying, "Behold, I will send you Elijah the prophet, and he shall turn the heart of the fathers to the children, and the heart of the children to their fathers;" [Malachi 4:5-6] he will yield up also to death that debt, which by his prolonged life he has delayed to render.
Theophylact - Now the Lord puts this forward to oppose the notion of the Pharisees, who held that Elias was the forerunner of the first advent, shewing that it led them to a false conclusion; wherefore he subjoins, "And how it is written of the Son of man, that He must suffer many things, and be set at nought." As if He had said, When Elias the Tishbite cometh, he will pacify the Jews, and will bring them to the faith, and thus be the forerunner of the second advent.
If then Elias is the forerunner of the first advent, how is it written that the Son of man must suffer? One of these two things therefore will follow; either that Elias is not the forerunner of the first advent, and thus the Scripture will be true; or that he is the forerunner of the first advent, and then the Scripture will not be true, which say that Christ must suffer; for Elias must restore all things, in which case there will not be an unbelieving Jew, but all, whosoever hear him, must believe on his preaching.
Bede - Or this, "And how it is written;" that is, in the same way as the prophets have written many things in various places concerning the Passion of Christ, Elias also, when he comes, is to suffer many things, and to be despised by the wicked.
Chrys. - Now as the Lord asserted that Elias was to be the forerunner of the second advent, so consequently He asserted that John was the forerunner of the first. Wherefore He subjoins, "But I say unto you, that Elias is indeed come."
Gloss. - He calls John Elias, not because he was Elias in person, but because he fulfilled the ministry of Elias; for as the latter will be the forerunner of the second advent, so the former has been that of the first.
Theophylact - For again, John rebuked vice, and was a zealous man, and a hermit like Elias; but they heard him not, as they will hear Elias, but killed him in wicked sport, and cut off his head.
Wherefore there follows, "And they have done unto him whatsoever they listed, as it is written of him."
Pseudo-Chrys., Vict. Ant. e Cat. in Marc. - Or else, the disciples asked Jesus, how it was written that the Son of man must suffer? Now in answer to this, He says, As John came in the likeness of Elias, and they evil intreated him, so according to the Scriptures must the Son of man suffer.
- text taken from Catena Aurea - Gospel of Mark by Saint Thomas Aquinas, translated by William Whiston, 1842