First Reading — Genesis 15:5-12, 17-18
Clement of Rome
On 15:5–6
Abraham, styled "the friend," [Isaiah 41:8] was found faithful, inasmuch as he rendered obedience to the words of God. He, in the exercise of obedience, went out from his own country, and from his kindred, and from his father's house, in order that, by forsaking a small territory, and a weak family, and an insignificant house, he might inherit the promises of God. For God said to him, "Get you out from your country, and from your kindred, and from your father's house, into the land which I shall show you. And I will make you a great nation, and will bless you, and make your name great, and you shall be blessed. And I will bless them that bless you, and curse them that curse you; and in you shall all the families of the earth be blessed." [Genesis 12:1-3] And again, on his departing from Lot, God said to him, "Lift up your eyes, and look from the place where you now are, northward, and southward, and eastward, and westward; for all the land which you see, to you will I give it, and to your seed forever. And I will make your seed as the dust of the earth, [so that] if a man can number the dust of the earth, then shall your seed also be numbered." [Genesis 13:14-16] And again [the Scripture] says, "God brought forth Abram, and spoke unto him, Look up now to heaven, and count the stars if you are able to number them; so shall your seed be. And Abram believed God, and it was counted to him for righteousness." [Genesis 15:5-6] On account of his faith and hospitality, a son was given him in his old age; and in the exercise of obedience, he offered him as a sacrifice to God on one of the mountains which He showed him. [Genesis 22:9]
Responsorial Psalm — Psalm 27:1, 7-8, 8-9, 13-14
Cyril of Jerusalem
On 26:14
[The Holy Spirit] is called Comforter, because he comforts and encourages us and "helps our weakness. For we do not know what we should pray for as we ought, but the Spirit himself pleads for us with unutterable groanings," that is, clearly, to God. Often a person for Christ's sake is treated with contumely and unjustly dishonored; martyrdom is at hand, tortures on every side, fire, swords, wild beasts and the abyss; but the Holy Spirit gently whispers, "Wait for the Lord," for your present sufferings are slight, while your rewards will be great; endure for a little while, and you will be with the angels forever. "The sufferings of the present time are not worthy to be compared with the glory to come that will be revealed in us." He portrays for the person the kingdom of heaven and even gives him a glimpse of the paradise of pleasure; and the martyrs, who must present their bodily countenances to their judges, are in spirit already in paradise, despise what appear to be hardships.
Second Reading — Philippians 3:17-4:1
Ignatius of Antioch
On 3:10
The last times are come upon us. Let us therefore be of a reverent spirit, and fear the long-suffering of God, lest we despise the riches of His goodness and forbearance. For let us either fear the wrath to come, or let us love the present joy in the life that now is; and let our present and true joy be only this, to be found in Christ Jesus, that we may truly live. Do not at any time desire so much as even to breathe apart from Him. For He is my hope; He is my boast; He is my never-failing riches, on whose account I bear about with me these bonds from Syria to Rome, these spiritual jewels, in which may I be perfected through your prayers, and become a partaker of the sufferings of Christ, and have fellowship with Him in His death, His resurrection from the dead, and His everlasting life. May I attain to this, so that I may be found in the lot of the Christians of Ephesus, who have always had intercourse with the apostles by the power of Jesus Christ, with Paul, and John, and Timothy the most faithful.
On 3:16
Being mindful of your love and of your zeal in Christ, which ye have manifested towards us, we thought it fitting to write to you, who display such a godly and spiritual love to the brethren, to put you in remembrance of your Christian course, "that ye all speak the same thing, being of one mind, thinking the same thing, and walking by the same rule of faith," [Philippians 3:16] as Paul admonished you. For if there is one God of the universe, the Father of Christ, "of whom are all things; " and one Lord Jesus Christ, our [Lord], "by whom are all things; " and also one Holy Spirit, who wrought in Moses, and in the prophets and apostles; and also one baptism, which is administered that we should have fellowship with the death of the Lord; and also one elect Church; there ought likewise to be but one faith in respect to Christ. For "there is one Lord, one faith, one baptism; one God and Father of all, who is through all, and in all."
On 3:18
And after the observance of the Sabbath, let every friend of Christ keep the Lord's Day as a festival, the resurrection-day, the queen and chief of all the days [of the week]. Looking forward to this, the prophet declared, "To the end, for the eighth day," on which our life both sprang up again, and the victory over death was obtained in Christ, whom the children of perdition, the enemies of the Saviour, deny, "whose god is their belly, who mind earthly things," who are "lovers of pleasure, and not lovers of God, having a form of godliness, but denying the power thereof." These make merchandise of Christ, corrupting His word, and giving up Jesus to sale: they are corrupters of women, and covetous of other men's possessions, swallowing up wealth insatiably; from whom may ye be delivered by the mercy of God through our Lord Jesus Christ!
On 3:18
Do ye also avoid those wicked offshoots of his, Simon his firstborn son, and Menander, and Basilides, and all his wicked mob of followers, the worshippers of a man, whom also the prophet Jeremiah pronounces accursed. Flee also the impure Nicolaitanes, falsely so called, who are lovers of pleasure, and given to calumnious speeches. Avoid also the children of the evil one, Theodotus and Cleobulus, who produce death-bearing fruit, whereof if any one tastes, he instantly dies, and that not a mere temporary death, but one that shall endure for ever. These men are not the planting of the Father, but are an accursed brood. And says the Lord, "Let every plant which my heavenly Father has not planted be rooted up." For if they had been branches of the Father, they would not have been "enemies of the cross of Christ," but rather of those who "killed the Lord of glory." But now, by denying the cross, and being ashamed of the passion, they cover the transgression of the Jews, those fighters against God, those murderers of the Lord; for it were too little to style them merely murderers of the prophets. But Christ invites you to [share in] His immortality, by His passion and resurrection, inasmuch as ye are His members.
On 3:18
These things I write to you, thou new olive-tree of Christ, not that I am aware you hold any such opinions, but that I may put you on your guard, as a father does his children. Beware, therefore, of those that hasten to work mischief, those "enemies of the cross of Christ, whose end is destruction, whose glory is in their shame." Beware of those "dumb dogs," those trailing serpents, those scaly dragons, those asps, and basilisks, and scorpions. For these are subtle wolves, and apes that mimic the appearance of men.
Gospel — Luke 9:28b-36
Origen
On 9:32
(ubi sup.) Now Jesus wishes not those things which relate to His glory to be spoken of before His passion. Hence it follows, And they kept it close. For men would have been offended, especially the multitude, if they saw Him crucified Who had been so glorified.
On 9:34
(in Matt. tom. 12.) Now His disciples being unable to bear this, fell down, humbled under the mighty hand of God, greatly afraid since they knew what was said to Moses, No man shall see my face, and lice. Hence it follows, And they feared as they entered into the cloud.