St. Peter, the fervent follower of Jesus Christ, for the profound confession of His Divinity: “Thou art the Christ, the Son of the Living God,” was deemed worthy by the Savior to hear in answer, “Blessed art thou, Simon … I tell thee, that thou art Peter [Petrus], and on this stone [petra] I build My Church” (Mt.16:16-18). On “this stone” [petra], is on that which thou sayest: “Thou art the Christ, the Son of the Living God” it is on this thy confession I build My Church. Wherefore the “thou art Peter”: it is from the “stone” [petra] that Peter [Petrus] is, and not from Peter [Petrus] that the “stone” [petra] is, just as the Christian is from Christ, and not Christ from the Christian. Do you want to know, from what sort of “rock” [petra] the Apostle Peter [Petrus] was named? Hear the Apostle Paul: “Brethren, I do not want ye to be ignorant,” says the Apostle of Christ, “how all our fathers were all under the cloud, and all passed through the sea; and all were baptized unto Moses in the cloud and in the sea; and did all drink the same spiritual drink: for they drank of that spiritual Rock that followed them: and that Rock was Christ” (1 Cor.10: 1-4). Here is the from whence the “Rock” is Peter.
– Saint Augustine, Bishop of Hippo in North Africa
– From https://oca.org/FeastSaintsViewer.asp?SID=4&ID=1&FSID=101840
