From the First Chapter
1 “The Revelation of Jesus Christ, which God gave to Him, and showed unto His servants things which must shortly come to pass, and signified it. Blessed are they who read and hear the words of this prophecy, and keep the things which are written.” The beginning of the book promises blessing to him that reads and hears and keeps, that he who takes pains about the reading may thence learn to do works, and may keep the precepts.
4. “Grace unto you, and peace, from Him which is, and which was, and which is to come.” He is, because He endures continually; He was, because with the Father He made all things, and has at this time taken a beginning from the Virgin; He is to come, because assuredly He will come to judgment.
“And from the seven spirits which are before His throne.” We read of a sevenfold spirit in Isaiah, — namely, the spirit of wisdom and of understanding, the spirit of counsel and might, of knowledge and of piety, and the spirit of the fear of the Lord.
5. “And from Jesus Christ, who is the faithful witness, the first-begotten of the dead.” In taking upon Him manhood, He gave a testimony in the world, wherein also having suffered, He freed us by His blood from sin; and having vanquished hell, He was the first who rose from the dead, and “death shall have no more dominion over Him,” but by His own reign the kingdom of the world is destroyed.
6. “And He made us a kingdom and priests unto God and His Father.” That is to say, a Church of all believers; as also the Apostle Peter says: “A holy nation, a royal priesthood.”
7. “Behold, He shall come with clouds, and every eye shall see Him.” For He who at first came hidden in the manhood that He had undertaken, shall after a little while come to judgment manifest in majesty and glory. And what says He?
12. “And I turned, and saw seven golden candlesticks; and in the midst of the seven golden candlesticks one like the Son of man.” He says that He was like Him after His victory over death, when He had ascended into the heavens, after the union in His body of the power which He received from the Father with the spirit of His glory.
13. “As it were the Son of man walking in the midst of the golden candlesticks.” He says, in the midst of the churches, as it is said in Solomon, “I will walk in the midst of the paths of the just,” whose antiquity is immortality, and the fountain of majesty.
“Clothed with a garment down to the ankles.” In the long, that is, the priestly garment, these words very plainly deliver the flesh which was not corrupted in death, and has the priesthood through suffering.
“And He was girt about the paps with a golden girdle.” His paps are the two testaments, and the golden girdle is the choir of saints, as gold tried in the fire. Otherwise the golden girdle bound around His breast indicates the enlightened conscience, and the pure and spiritual apprehension that is given to the churches.
14. “And His head and His hairs were white as it were white wool, and as it were snow.” On the head the whiteness is shown; “but the head of Christ is God.” In the white hairs is the multitude of abbots like to wool, in respect of simple sheep; to snow, in respect of the innumerable crowd of candidates taught from heaven.
“His eyes were as a flame of fire.” God's precepts are those which minister light to believers, but to unbelievers burning.
16. “And in His face was brightness as the sun.” That which He called brightness was the appearance of that in which He spoke to men face to face. But the glory of the sun is less than the glory of the Lord. Doubtless on account of its rising and setting, and rising again, that He was born and suffered and rose again, therefore the Scripture gave this similitude, likening His face to the glory of the sun.
15. “His feet were like yellow brass, as if burned in a furnace.” He calls the apostles His feet, who, being wrought by suffering, preached His word in the whole world; for He rightly named those by whose means the preaching went forth, feet. Whence also the prophet anticipated this, and said: “We will worship in the place where His feet have stood.” Because where they first of all stood and confirmed the Church, that is, in Judea, all the saints shall assemble together, and will worship their Lord.
16. “And out of His mouth was issuing a sharp two-edged sword.” By the twice-sharpened sword going forth out of His mouth is shown, that it is He Himself who has both now declared the word of the Gospel, and previously by Moses declared the knowledge of the law to the whole world. But because from the same word, as well of the New as of the Old Testament, He will assert Himself upon the whole human race, therefore He is spoken of as two-edged. For the sword arms the soldier, the sword slays the enemy, the sword punishes the deserter. And that He might show to the apostles that He was announcing judgment, He says: “I came not to send peace, but a sword.” And after He had completed His parables, He says to them: “Havey3ye understood all these things? And they said, We have. And He added, Therefore is every scribe instructed in the kingdom of God like a man that is a father of a family, bringing forth from his treasure things new and old,” — the new, the evangelical words of the apostles; the old, the precepts of the law and the prophets: and He testified that these proceeded out of His mouth. Moreover, He also says to Peter: “Go to the sea, and cast a hook, and take up the fish that shall first come up; and having opened its mouth, you shall find a stater (that is, two denarii), and you shall give it for me and for you.” And similarly David says by the Spirit: “God spoke once, twice I have heard the same.” Because God once decreed from the beginning what shall be even to the end. Finally, as He Himself is the Judge appointed by the Father, on account of His assumption of humanity, wishing to show that men shall be judged by the word that He had declared, He says: “Do you think that I will judge you at the last day? Nay, but the word,” says He, “which I have spoken unto you, that shall judge you in the last day.” And Paul, speaking of Antichrist to the Thessalonians, says: “Whom the Lord Jesus will slay by the breath of His mouth.” And Isaiah says: “By the breath of His lips He shall slay the wicked.” This, therefore, is the two-edged sword issuing out of His mouth.
15. “And His voice as it were the voice of many waters.” The many waters are understood to be many peoples, or the gift of baptism that He sent forth by the apostles, saying: “Go, teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost.”
Source: Commentary on the Apocalypse of the Blessed John (New Advent)