(Ver. 21 seq.) While they were conversing in Galilee, Jesus said to them: The Son of Man is to be handed over to the hands of men, and they will kill him; and on the third day he will rise again. And they were greatly saddened. He always mixes sorrows with prosperity, so that when they come suddenly, they do not terrify the apostles; but they are carried by their prepared minds: For if they are saddened by his impending death, they should be joyful at the news of his resurrection on the third day. Furthermore, their grief and sorrow are not due to disbelief (otherwise they would have known that Peter was rebuked because he did not understand the things of God, but those of men), but rather because out of love for their master, they are willing to hear nothing negative or humiliating about him.
This seems to be so like a warning He had given above, that a man might easily say that the Lord now repeated what He had said before; yet is it not so; He had not before said that He must be betrayed, but we hear now not only that He must be betrayed, but that He must be betrayed into the hands of men. The Son of Man indeed was delivered up by God the Father according to the Apostle (Rom. 8:32.), but different powers gave him up into the hands of men.
By this announcement of the Lord the disciples were made very sorrowful, not attending to that He said, And shall rise again the third day, nor considering what He must be to whom the space of three days was enough to destroy death.
I think we have an obligation to examine this, too: that Jesus was delivered into the hands of men, not by men into the hands of men but by powers to whom the Father delivered his Son on behalf of us all. In the very act of being delivered and coming under the power of those to whom he was delivered, he “destroyed him who had the power of death.” For “through death he destroyed him who has the power of death, that is, the devil, and delivered all those who through fear of death were subject to lifelong bondage.”
In case they say “Why do we delay here so long?” again he tells them about his Passion. Hearing of it, they did not even want to see Jerusalem.… Peter had been rebuked, those around Moses and Elijah had spoken with him and had called the thing glory, and … the Father had spoken from above; after so many miracles had taken place and the resurrection was close by (for he said that he would not long remain in death but would rise on the third day)—not even thus could they endure it. But “they were distressed,” and not simply “distressed” but “greatly distressed.” This happened because they did not yet recognize the power of what he said. But Mark and Luke imply it; the former saying that “they did not understand the saying and they were afraid to ask”; the latter saying that “it was concealed from them that they should not perceive it, and they were afraid to ask him about this saying.” Yet if they did not know it, why were they distressed? Because they were not totally ignorant.They knew that he would die, having heard it continually. But as yet they did not know clearly what kind of death this was to be, or that there would be a speedy release from it, or that it would work innumerable blessings, or what this resurrection might be. They did not know it, and so they were distressed, for they greatly adored their Master.
Thus does He ever mix the joyful and the grievous; if it grieves them that He is to be put to death, they ought to be gladdened when they hear, And shall rise again the third day.
That they were thus made exceeding sorrowful, came not of their lack of faith; but out of their love of their Master they could not endure to hear of any hurt or indignity for Him.
Whenever the Lord speaks of future disaster, he always teaches its close relation with the happiness of redemption, so that when disasters suddenly come they do not terrify the apostles but may be borne by hearts that have premeditated them. If it saddens them because he is going to be killed, it ought to make them rejoice that it says, “On the third day he will arise again.” Further, their distress, in fact their great distress, does not come from lack of faith—elsewhere also they knew that Peter had been rebuked because he did not consider what belonged to God but what belonged to men—but because their love of their Master does not let them hear anything ominous or humiliating.
Therefore he brought the disciples to the mountain and showed them the glory with which he will shine on the universe in the future. Then coming down from the mountain he freed a person from a rough and evil spirit. It was altogether necessary for him to undergo his saving Passion for us and to suffer the violence of the Jews. When this happened, it was quite likely that the disciples would be alarmed and would ponder it and say among themselves: “He has raised so many from the dead by divine power, he commands the seas and winds, he overwhelms Satan with his words—how has he now been taken and fallen to the noose of his murderers? Then maybe we were deceived when we thought that he was God?” So that they should know the future fully and completely, therefore, he foretells to them the mystery of the Passion.
Or, fasting is here understood generally as abstinence not from food only, but from all carnal allurements, and sinful passions. In like manner prayer is to be understood in general as consisting in pious and good acts, concerning which the Apostle speaks, Pray without ceasing. (1 Thess. 5:17.)
The Lord often foretold to His disciples the mysteries of His passion, in order that when they come to pass, they might be the lighter to them from having been known beforehand.
Now this arose from their being ignorant as yet of the force of His sayings. This Mark and Luke indirectly expressing said, the one, "They understood not the saying, and were afraid to ask Him:"the other, "It was hid from them, that they perceived it not, and they feared to ask Him of that saying."
And yet if they were ignorant, how were they sorry? Because they were not altogether ignorant; that He was to die they knew, continually hearing it, but what this death might be, and that there would be a speedy release from it, and that it would work innumerable blessings, as yet they knew not clearly; nor what this resurrection might be: but they understood it not, wherefore they grieved; for indeed they clung very earnestly to their Master.
He continually foretells the Passion, so that no one would think that He suffered unwillingly, and also, to train them so that they would not be shaken by the unexpected when it occurred. To the sorrow He weds the joy, that He will rise.
[AD 420] Jerome on Matthew 17:21-23