1 Before these words, which we are now, with the Lord's help, to make the subject of discourse, Jesus had said, “These things have I spoken unto you, that in me ye might have peace;” which we are to consider as referring, not to the later words uttered by Him immediately before, but to all that He had addressed to them, whether from the time that He began to account them disciples, or at least from the time after supper when He commenced this admirable and lengthened discourse. He gave them, indeed, such a reason for speaking to them, that either all He ever spoke to them may with the utmost propriety be referred to that end, or those especially, as His last words, which He now spoke when on the eve of dying for them, after that he who was to betray Him had quitted their company. For He gave this as the cause of His discourse, that in Him they might have peace, just as it is wholly on this account that we are Christians. For this peace will have no temporal end, but will itself be the end of every pious intention and action that are ours at present. For its sake we are endowed with His sacraments, for its sake we are instructed by His works and sayings, for its sake we have received the earnest of the Spirit, for its sake we believe and hope in Him, and according to His gracious giving are enkindled with His love: by this peace we are comforted in all our distresses, by it we are delivered from them all: for its sake we endure with fortitude every tribulation, that in it we may reign in happiness without any tribulation. Fitly therewith did He bring His words to a close, which were proverbs to the disciples, who as yet had little understanding, but would afterwards understand them, when He had given them the Holy Spirit of promise, of whom He had said before: “These things have I spoken unto you being yet present with you. But the Comforter, the Holy Ghost, whom the Father will send in my name, He shall teach you all things, and bring all things to your remembrance, whatsoever I have said unto you.” Such, doubtless, was to be the hour, wherein He promised that He would no more speak unto them in proverbs, but show them openly of the Father. For these same words of His, when revealed by the Holy Spirit, were no more to be proverbs to those who had understanding. For when the Holy Spirit was speaking in their hearts, there was not to be silence on the part of the only-begotten Son, who had said that in that hour He would show them plainly of the Father, which, of course, would no longer be a proverb to them when now endowed with understanding. But even this also, how it is that both the Son of God and the Holy Spirit speak at once in the hearts of their spiritual ones, yea the Trinity itself, which is ever inseparably at work, is a word to those who have, but a proverb to those who are without, understanding.
2. When, therefore, He had told them on what account He had spoken all things, namely, that in Him they might have peace while having distress in the world, and had exhorted them to be of good cheer, because He had overcome the world; having thus finished His discourse to them, He then directed His words to the Father, and began to pray. For so the evangelist proceeds to say: “These things spoke Jesus, and lifted up His eyes to heaven, and said: Father, the hour has come; glorify Your Son.” The Lord, the Only-begotten and coeternal with the Father, could in the form of a servant and out of the form of a servant, if such were needful, pray in silence; but in this other way He wished to show Himself as one who prayed to the Father, that He might remember that He was still our Teacher. Accordingly, the prayer which He offered for us, He made also known to us; seeing that it is not only the delivering of discourses to them by so great a Master, but also the praying for them to the Father, that is a means of edification to disciples. And if so to those who were present to hear what was said, it is certainly so also to us who were to have the reading of it when written. Wherefore in saying this, “Father, the hour has come; glorify Your Son,” He showed that all time, and every occasion when He did anything or suffered anything to be done, were arranged by Him who was subject to no time: since those things, which were individually future in point of time, have their efficient causes in the wisdom of God, wherein there are no distinctions of time. Let it not, then, be supposed that this hour came through any urgency of fate, but rather by the divine appointment. It was no necessary law of the heavenly bodies that tied to its time the passion of Christ; for we may well shrink from the thought that the stars should compel their own Maker to die. It was not the time, therefore, that drove Christ to His death, but Christ who selected the time to die: who also fixed the time, when He was born of the Virgin, with the Father, of whom He was born independently of time. And in accordance with this true and salutary doctrine, the Apostle Paul also says, “But when the fullness of the time had come, God sent forth His Son;” and God declares by the prophet, “In an acceptable time have I heard You, and in a day of salvation have I helped you;” and yet again the apostle, “Behold, now is the accepted time; behold, now is the day of salvation.” He then may say, “Father, the hour has come,” who has arranged every hour with the Father: saying, as it were, “Father, the hour,” which we fixed together for the sake of men and of my glorification among them, “has come, glorify Your Son, that Your Son also may glorify You.”
Source: Tractates on the Gospel of John (New Advent)