The great commentary of Cornelius a Lapide:
Verse 18- And I say unto thee that thou art Peter, and upon this rock I will build my church. “And I,” in Greek, “κα̉γὼ” i.e., but I, or now I, give back to thee as a reward, and I in turn say and promise: for as S. Jerome saith. “Christ pays back the testimony of the Apostle concerning Himself.” Peter had said, “Thou art the Christ—the Son of the living God:” this true confession received a reward, namely, “Thou art Peter.” I therefore who am the very Son of God as thou hast confessed, I the Son of God tell and assure thee, and by saying it, I make and constitute thee, Peter, so that after Me thou mayest become the rock of the Church. Christ had promised this name to Simon (S. John i. 42), Saying, “Thou shalt be called Cephas, which is interpreted Peter:” but in this place He fulfils the promise, and gives him the name of Peter in fact. S. Leo (Ser. III, Anniver. Ascens.) thus expounds: “And I say unto thee, that even as My Father hath made known to thee My excellence, so do I also make known to thee that thou art Peter, i.e., inasmuch as I am the inviolable Rock, &c., so likewise thou art a rock, because thou art strengthened by My strength, and the things which are Mine by My own power are thine by participation with Me.”
Thou are Peter, and upon this role I will build My Church. The meaning is, thou art Peter; that is, the rock of the Church: for upon thee as upon a most solid rock I will build My Church: for the WORD declares and gives the reason why he is Peter, that is to say, “Thou art Peter, because upon thee as upon a rock I will build My Church.” S. Augustine (Tract 27, upon John, and.B. 1 Retract, C. 1) says, “Upon this Rock, that is upon Myself, because the rock was Christ,” 1 Cor. x. 4. Calvin, (B. 4, Inst. c. 6), and the heretics eagerly follow this interpretation, that they may overthrow the authority and the primacy of Peter and the Pope. But that Peter himself is here called the rock, the rest of the Fathers almost universally agree. Maldonatus and Bellarmine (B. 1, concerning the Roman Pontiff, e. 10) quote them at large. The meaning then is this, thou art “Kepha,” or “Cephas,” i.e., a rock or a very hard and very firm stone, for this is the signification of the Hebrew “Keph,” and of the Chaldee and Syriac “Kepha,” marked out and ordained by Me, that after My death, and the gift of the Holy Ghost at Pentecost, having been entirely solidified and made strong, thou mayest become the foundation of the Church which I will build upon thee. For before the coming of the Holy Ghost, Peter was very far from being the rock of the Church; yea through fear he denied Christ in His Passion. So then the word “Peter,” and “Petra,” denotes the firmness of S. Peter as a prince of the Church, and of his successors the Pontiffs, and their constancy in the faith and religion of Christ. Thus among others, Angelus Caninius on the Hebrew names of the New Testament c. xu 1.
Moreover, that Peter is here called the Rock, is proved first, by the pronoun “this,” upon “this rock;” for since “this” is demonstrative it ought thus to be understood, viz.:—this rock of which I have spoken, and to whom I speak, i.e., thou art Peter the rock of the Church, and upon thee as upon a rock I will build My Church. For there had been no mention made of any other rock to which the pronoun “this” could refer, except Peter. It is otherwise in 1 Cor. x., for there it is said “they drank of that spiritual rock which followed them, and that rock was Christ.” Here the word rock precedes, which he explains by saying, that it was so, typically, that is to say, represented Christ: as if Christ had spoken in French He would have said “Tu es Pierre, et sur cest pierre je bastiray mon eglise.”
You may say, Christ said not thou art petra, but thou art Petrus, and so deny that the pronoun this refers to Peter. I answer, that Christ is said to have spoken in Syriac, thou art kepha, and upon this kepha I will build, &c. For kepha means a rock, and hence Peter in Syriac was called kepha. But the Greek translator, who is followed by the Latin, gave the masculine form of the noun—namely petrus rather than petra, which is feminine: but πέτρος and πέτρα in Greek equally signify a rock or a stone. Peter therefore is the same word as petra, but the translator made a variation for the sake of elegance, and rendered it thou art Peter and upon this petra, not upon this Petros, as in a true and proper sense he might have done, both because petra in Greek is more frequently used for a rock or a stone than petros, and because houses are properly built upon stones, not upon men. Beza allows this when he says “the Lord speaking in Syriac did not make use of a surname, but said cepha in both places, as in the vernacular the word pierr is used both as a proper and a common noun. In Greek, likewise, πέτρος and πέτρα differ only in their termination, not in their meaning.” Thus far correctly, but mistakenly he adds, “Matthew, or whoever was his translator, seems by this difference of interpretation to have intended that Peter, who is a part of the building, should be distinguished from the rock itself on which the building stands, that is from Christ; likewise that Peter himself should be distinguished from the promise of the faith which is common to the whole Church, as ancient writers also clearly prove, in order that Antichrist (so the heretics calls the Roman Pontiff) may become most ridiculous when his followers endeavour to establish his tyranny from this passage.” How petulantly and falsely Beza writes may be seen and learnt from the original passages of the Fathers which Bellarmine and Maldonatus cite, as I have already said. Besides, the text of Scripture itself is to be preferred to the translator: nor had the Greek translator a meaning different from the Syriac text, as I have previously said. I omit many other proofs, which either from what has been said, or from what will be said, will show the falsity of Beza’s conclusion.
Secondly—The same thing is plain from this, that there would be a want of connection to say thou art Peter and upon Myself the Rock I will build My church. In this indeed there would be a lessening of the speech, and an overthrow of the benefit bestowed. For Peter might say to Christ, “I am Peter, that is the rock of the Church, how then dost thou build Thy Church not upon me but upon Thyself?”
Thirdly—Because all that goes before and that follows refer to Peter alone: “and I,” he saith, “say to thee, 0 Peter, that is, I give and assign to thee as the reward and prerogative of thy great faith and confession, that after Myself, and after My death and resurrection, I will make thee the rock and foundation of the Church;” for this is the meaning of I will build My Church.
Fourthly—Because the original oriental versions agree together in this, that petrus is the very same word as petra, and petra as petrus, whence they give the same name Kepha to Petrus and Petra. Christ therefore as Angelus Caninius says, spoke thus in Syriac: ant kepha, veal kepha hadden ebne iat tsibbuti; or as the Syriac Gospel has it, ant hu kipha, veal hada kipha ebne leidti, that is, thou art Cepha, that is a rock, and upon this Cepha, that is petra, meaning upon thee, who art Peter or a rock, “I will build my Church.” Moreover, the Hebrew Gospel, which Sebastian Munster has edited as authentic, and as written by S. Matthew himself, has in like manner atta kepha, veal kepha hazzot ebne eth macpeli. So also the Armenian Gospel: Is bim, he saith e vera ais bim, that is, thou art a rank, and upon this rock I will build, &c.; and the Arabic Gospel, ant alsachra va ala hada, alsachra abni baidti, thou art a rock, and upon that rock I will build my Church. The Æthiopic Gospel has Anta quoqueh va dibazati, quoqh annesa lebeita Christianei, that is, thou are a rock and upon this rock I will build the Christian house—that is the Church. The Coptic also has, but I say unto thee that thou art this Peter, I will found my Church upon this rock, which is none else than this Peter, otherwise there would be no connection, for he gives the reason, the because, why he will build the Church upon a rock, because indeed Peter will be a solid rock on which the whole Church being founded may rest securely as upon a strong foundation. The Persian is, “I say unto thee that thou art sanac,” i.e., a rock, “and upon this sanac,” that is, rock, “I will build my Church.” Moreover, the Persian paraphrase explains sanac as a rock, adding, thou art the rock, that is, foundation and judge. (Vide Peter Victor in Annotat. ad N. T. pp. 105, 102, where he gives at length all these versions.)
To S. Augustine it is replied that he was misled by his ignorance of the Hebrew and Syriac languages, and therefore thought that petrus was something different from petra, and that Peter was as it were called appellatively from it Petreius, although it appears from the Syriac that Petrus and Petra are the same. Again, S. Augustine admits as probable the explanation of those who say that Peter is the rock of the Church; and in this respect he is at issue with Calvin, who is of opinion that such an explanation is blasphemy against Christ. Listen to S. Augustine in his sermon on the Chair of Peter. “Lastly, for strengthening the devotion of the churches he is called the rock; as saith the Lord, ‘thou art Peter, and upon this rock I will build My Church;’ for he is called the rock because he first laid the foundations of the faith for the nations, and like an immovable rock he holds the joints and the superstructure of the entire Christian edifice. Peter then is called a rock on account of devotion, and the Lord is called a rock on account of strength; as saith the Apostle, ‘they drank of that spiritual Rock which followed them, and that Rock was Christ.’ Rightly does he deserve an association in name who had obtained an association in work. Peter lays the foundation, Peter plants; the Lord gives the increase, the Lord waters.” The same Augustine (Serm. 16 de Sanctis) says, “Worthy was Peter to be a foundation for building up the people of God, to be a pillar for support, a key to the kingdom.”
In fine, even if that exposition of S. Augustine were allowed, although it is not the true one, still it may thence be proved that Peter, after Christ, who is the Rock and Corner Stone of the Church, is still the next foundation, rock, or stone of the Church. For then the sense would be, I am the Rock upon which I will build the Church; but thou, 0 Peter, art next unto Me, and the next rock of the Church, upon whom immediately after Myself I will build My Church, and therefore thee only I call Peter, who before wast called Simon. By the same arguments the Magdeburg Centuriators (l. 1. cent. 1, chap. 4.) are refuted, and the Genevan ministers who in their Bibles expound thus—“upon this rock, that is, upon this confession or faith—viz.: that I am the Son of God.” For nowhere previously has this confession been called a rock, as Peter immediately before was called Cephas, that is, a rock.
You may say, some of the Fathers, by the rock, understand the faith which Peter confessed and set forth. So S. Chrysostom, S. Hilary (l. 6 de Trinit.), S. Cyril. (l. 4 de Trinit.), S. Ambrose (l. 6 in Luc. c. 9). I answer, these Fathers do not mean the faith abstractedly, but the faith as it was in Peter, and consequently they take Peter himself to be the rock of the Church, as they themselves afterwards fully explain. They hold that Peter, for the merit of his faith received the dignity of a rock in the Church. As SS. Hilary and Chrysostom say expressly; for on account of that faith he had deserved to be himself the foundation of the Church, and that his faith should never fail, but that he should confirm and strengthen others in the faith. (S. Luke xxii. 32.) For the Church is fashioned and renewed not of faith, but of faithful men, who are as it were its parts (for the Church is nothing else than the company of the faithful), wherefore, likewise, in order that the head of the Church may be of the same nature as the body, that head must be a faithful man—that is to say, Peter and the Pontiff. The faith then is the reason of the founding, but the foundation is Peter himself. So S. Chrysostom, Cyril (l. 4 de Trinit.) and S. Ambrose, Bellarmine (l. 1 de Pont. c. 10) where he refutes both Erasmus and Chytræus, who follow Origen, who allegorizes after his custom, and understands by the rock all the faithful. In this way indeed the whole Church would be the rock, for the whole Church consists of none other than the faithful; but where then would be the walls, the floors, and the roof of the Church? Of what then shall these be built? (See also Gretser in defence of Bellarm, l. 3. c. 5.)
Lastly, Christ bestowed this gift upon Peter as the future Pontiff of the Church; wherefore He gave the same gift to all the other Pontiffs, his successors, and that for the good of the Church, that it might be strengthened by them as by a rock, in the faith and religion of Christ. Wherefore, S. Bernard (l. 2, de Consid.) saith to Pope Eugenius, “Who art thou? A great priest—the chief Pontiff. Thou art the prince of bishops, thou art the heir of the Apostles, thou art Abel in primacy, Noah in government, Abraham in the patriarchate; in order, thou art Melchisedeck, in dignity Aaron, in authority Moses, in judgeship Samuel, in power Peter, in unction a Christ. To thee the keys have been delivered, the sheep entrusted.”
And upon this rock. From hence it is plain that like as Cephas is derived from cepha, so is Peter from petra, indeed that he is the same as petra, as I have already shown. Wherefore, when Optatus Milevit. (l. 2, against Parmen.) and others derive Cephas from the Greek κεφαλή, that is, a head—they do it by a congruous allusion, not by a real etymology. By a similar allusion, S. Gregory Nazianzen (Orat. on the Passover) derives Phase or Pascha—which is a Hebrew word, as everybody knows (Exod. xii.), from the Greek πάσχειν, that is, to suffer. For in the Passover happened the Passion of Christ, and His immolation as the Paschal Lamb. Moreover, Christ gave this name of rock, rather than other names (such as pillar, tower, anchor, foundation, &c.), because this name of rock is given in Scripture to Christ Himself (Isaiah xxviii. 16; Psalm cxviii. 22; Matthew xxi 42.) He communicated, therefore, a share in His own name, together with His dignity and office. Thus S. Jerome; and S. Gregory (On the Seven Penitential Psalms) says: “Christ is the rock, from which rock Peter received his name, and upon which He said that He would build.” Listen to S. Leo (Serm. 3, On the Anniversary of his Accession), where he introduces Christ as speaking thus to Peter: “Since I am the rock, I the cornerstone, who make of both one; I the foundation, besides which no one can lay any other; nevertheless thou art a rock likewise, because thou art strengthened by My strength in order that what things are Mine by Mine own power, may be thine also through participation with Me: and upon this rock I will build My Church; upon this strength He says, I will construct an eternal temple, &c.”
I will build My Church. That is to say, I therefore call thee Peter and the rock, because as a house is built upon a rock that it may rest firm and immovable upon it against every blast of the winds, so will I build upon thee, 0 Peter, as upon a most solid rock, My Church; that resting upon thee, it may abide firm against all the attacks of heretics and wicked men, and that thou mayest keep and sustain it in the true faith and worship of God, in like manner as a rocky foundation sustains and holds together the entire house which is built upon it. Thus S. Ambrose (Serm. 4) saith: “Peter is called the rock, because—like an immovable rock—he sustains the joints and the mass of the whole Christian edifice.”
You may say all the Apostles are the foundation of the Church, as is plain from Eph. ii. 20, and Apoc. xxi. 20; so then Peter only is not the rock of the Church. I answer, that Peter is the rock and the foundation of the whole Church and of the entire body of the faithful, and therefore of the Apostles themselves. For the office of Peter—who is primate and chief—was to retain, direct, and strengthen the Apostles in faith, religion, and duty, and if at any time they should err, to correct them. Whence S. Jerome (l. 1, contra Jovin.) says: “Wherefore among twelve one is chosen, that by the appointment of a head, occasion of schism might be taken away.” And S. Cyprian (Tract on the Unity of the Church) says, “the primacy is given to Peter that it might be shown there is one Church of Christ and one Chair.”
Observe, Christ in this place promises by two metaphors, as S. Jerome says, that after His death and resurrection He will give to Peter the principality of the Church. The first metaphor is that of a foundation or foundation rock. For that thing, which in a building is the rock and foundation, in a body is the head, in a state the ruler, in a kingdom the king, in a church the pontiff. The second metaphor is that of the keys: for keys are only given to kings and rulers.
Observe, secondly: to build the Church upon this rock, signifies two things. First, that upon this reasonable stone—namely, Peter, as the head of all the Apostles—the care and government of the whole Church devolve next after Christ. Thus S. Chrysostom (Hom. 55), S. Ambrose (Serm. 57), S. Gregory (l. 4, Epist. 32). Secondly, that the Church rests upon and is strengthened by Peter as a foundation, as the Vicar of Christ, so that it cannot err in matters of faith. Whence Peter, on account of his lofty confession of faith, received grace from Christ to become and to be appointed this foundation rock.
And this is the meaning of SS. Hilary, Chrysostom, Cyril—and Nyssen, in the end of his book (Contra Judæos)—when they say that the Church was built by Christ upon the faith and confession of Peter, as I have explained above. Moreover, S. Chrysostom in this place lays stress upon the words I will build, and says: “They are similar to those words ‘God said,’ in the first chapter of Genesis, by which words all things were created and subsist.” In like manner he says: “I will build, hath wrought all, even though tyrants oppose, soldiers fight, the people rage, custom struggles. For the word of God coming like a vehement fire, hath burnt up the thorns, hath cleansed the fields, hath prepared the ground, hath raised the building on high, &c.” S. Jerome also (Epist. 57), consulting Pope Damasus whether we may say there are three Hypostases in the Holy Trinity or only one—thus addresses him: “I am speaking with the successor of the fisherman, and the disciple of the Cross. I, following none first, except Christ, am united to your Blessedness; that is, in communion with the See of Peter. I know that upon that rock the Church is built. Whosoever eateth the Lamb outside of this house is profane; if any man be not in the ark of Noah, he shall perish in the swelling of the deluge.”
And the gates of hell shall not prevail against it. Namely, against the Church, because it has been founded upon Peter and his successors, as upon a most solid rock.
The gates of hell, i.e., the infernal city, meaning all hell, with its entire army of demons, and with the whole power of Lucifer its king. For hell and the city of God, i.e., the Church, are here put in opposition. When S. Augustine wrote his work de Civitate Dei, in the beginning of which he speaks of the two opposite cities; the one of God which is the Church; the other of the devil, i.e., of demons and wicked men: he takes the gates of hell to mean heresies, and heresiarchs; for they fight against the faith of Peter and the Church, and they proceed from hell and are stirred up by the devil. So S. Epiphanius (in Ancoratu), not far from the beginning. There are here the two figures of speech—synecdoche and metonymy; for by the gates he means the whole city, both because the gate is the entrance into a city, and because the chief defences and strength of a city are wont to be at the gates, because if they and the adjoining walls are safe, the city is safe, if they are taken, the city is taken.
Shall not prevail. Heb. lo juchelu la, i.e., shall not be able to stand against it—namely, the Church. So S. Hilary and Maldonatus. More simply, shall not prevail, i.e., shall not conquer or overcome, or pull down the Church. For this is the meaning of the original Greek. We have here the figure of speech, miosis: for little is said but much is meant; not only that the Church shall not be conquered, but that she shall conquer and subdue under her all heretics, tyrants, and every other enemy, as she overcame Arians, Nestorians, Pelagians, Nero, Decius, Diocletian, &c. Therefore by this word Christ first animates his Church that she should not be faint hearted when she sees herself attacked by all the power of Satan and wicked men. In the second place, He as it were sounds a trumpet for her, that she may always watch with her armour on against so many enemies, who attack her with extreme hatred. Thirdly, He promises to her, as well as to her head, Peter, i.e., the Pontiff—victory and triumph over them all. Again, Christ and the Holy Ghost assist with special guidance her head, the Roman Pontiff, that he should not err in matters of faith, but that he may be firm as an adamant, says S. Chrysostom, and that he may rightly administer and rule the Church, and guide it in the path of safety, as Noah also directed the ark that it should not be overwhelmed in the deluge. Wherefore S. Chrysostom (Hom. de Verb. Isaiah) says: “It were more easy for the sun to be extinguished than for the Church to fail;” and again, “what can be more powerful than the Church of God: the barbarians destroy fortifications, but not even the devils overcome the Church. When it is attacked openly, it conquers; when it is attacked by treachery, it overcomes.” S. Augustine on the Psalms against the Donatists, says: “Reckon up the Bishops even from the very Pontificate of Peter. That is the very rock which the proud gates of hell conquer not.” This has been made especially plain in the conversion of all nations, specially of Rome and the Romans. For Rome being the head, both of the world and of idolatry, where the idols of all nations were worshipped, has been converted from them by S. Peter and his successors, and has bowed down her proud head to the cross of Christ, which thing is of all miracles the greatest.