The interpretation timeline
John 21:19 Douay-Rheims

And this he said, signifying by what death he should glorify God. And when he had said this, he saith to him: Follow me.

A.D. 407 – 1871 8 witnesses 11 excerpts

Patristic

before A.D. 750
407
A.D.
John Chrysostom Patristic
A.D. 347–407
“(Hom. lxxxviii) He says, Whither thou wouldest not, with reference to the natural reluctance of the soul to be separated from the body; an instinct implanted by God to prevent men putting an end to themselves. Then raising the subject, the Evangelist says, This spake He, signifying by what death he should glorify God: not, should die: he expresses himself so, to intimate that to suffer for Christ was the glory of the sufferer. (non occ.). But unless the mind is persuaded that He is very God, the sight of Him can in no way enable us to endure death. Wherefore the death of the saints is certainty of divine glory.”
Source
“(Hom. lxxxviii) The Evangelist then corrects the opinion taken up by the disciples.”
430
A.D.
Augustine of Hippo Patristic
A.D. 354–430
“(Tract. cxxiv) Our Lord having foretold to Peter by what death he should glorify God, bids him follow Him. And when He had spoken this, He saith unto him, Follow Me. Why does He say, Follow Me, to Peter, and not to the others who were present, who as disciples were following their Master? Or if we understand it of his martyrdom, was Peter the only one who died for the Christian truth? Was not James put to death by Herod? Some one will say that James was not crucified, and that this was fitly addressed to Peter, because he not only died, but suffered the death of the cross, as Christ did.”
Source
“(Tract. cxxiv.) Or perhaps he will allow that John still lies in his sepulchre at Ephesus, but asleep, not dead; and will give us a proof, that the soil over his grave is moist and watery, owing to his respiration. But why should our Lord grant it as a great privilege to the disciple whom He loved, that he should sleep this long time in the body, when he released Peter front the burden of the flesh by a glorious martyrdom, and gave him what Paul had longed for, when he said, I have a desire to depart and be with Christ? If there really takes place at John’s grave that which report says, it is either done to commend his precious death, since that had not martyrdom to commend it, or for some other cause not known to us. Yet the question remains, Why did our Lord say of one who was about to die, I will that he tarry till I come? It may be asked too why our Lord loved John the most, when Peter loved our Lord the most? I might easily reply, that the one who loved Christ the more, was the better man, and the one whom Christ loved the more, the more blessed; only this would not be a defence of our Lord’s justice. This important question then I will endeavour to answer. The Church acknowledges two modes of life, as divinely revealed, that by faith, and that by sight. The one is represented by the Apostle Peter, in respect of the primacy of his Apostleship; the other by John: wherefore to the one it is said, Follow Me, i. e. imitate Me in enduring temporal sufferings; of the other it is said, I will that he tarry till I come: as if to say, Do thou follow Me, by the endurance of temporal sufferings, let him remain till I come to give everlasting bliss; or to open out the meaning more, Let action be perfected by following the example of My Passion, but let contemplation wait inchoate till at My coming it be completed: wait, not simply remain, continue, but wait for its completion at Christ’s coming. Now in this life of action it is true, the more we love Christ, the more we are freed from sin; but He does not love us as we are, He frees us from sin, that we may not always remain as we are, but He loves us heretofore rather, because hereafter we shall not have that which displeases Him, and which He frees us from. So then let Peter love Him, that we may be freed from this mortality; let John be loved by Him, that we may be preserved in that immortality. John loved less than Peter, because, as he represented that life in which we are much more loved, our Lord said, I will that he remain (i. e. wait) till I come; seeing that that greater love we have not yet, but wait till we have it at His coming. And this intermediate state is represented by Peter who loves, but is loved less, for Christ loves us in our misery less than in our blessedness: and we again love the contemplation of truth such as it will be then, less in our present state, because as yet we neither know nor have it. But let none separate those illustrious Apostles; that which Peter represented, and that which John represented, both were sometime to be.”
Source

Scholastic

c. 1100 – 1500
1107
A.D.
“When our Lord says to Peter, Follow Me, He confers upon him the superintendence over all the faithful, and at the same time bids him imitate Him in every thing, word and work. He shews too His affection for Peter; for those who are most dear to us, we bid follow us.”
1270
A.D.
Thomas Aquinas Catholic
1225–1274
“After the Evangelist has set forth what the Lord showed to Peter, here he narrates what he showed to John, that is, to himself; and first the commendation of the disciple is set down; second, the commendation of his own Gospel, at the place, "Now there are also many other things which Jesus did." Concerning the first, first the occasion of the commendation is set down; second, the commendation of the disciple himself is added, at the place, "Peter, turning, saw that disciple whom Jesus loved." Now the occasion of the commendation of John was Christ's invitation, inviting Peter to follow: for when he had said these things, namely concerning the office and the martyrdom, Jesus said to Peter, "Follow me" — according to Augustine, as regards martyrdom, namely by suffering for me: for it is not enough to suffer in just any way, but only by following Christ, that is, for his sake. Luke 6:22: "Blessed shall you be when men hate you for the Son of man's sake"; 1 Peter 2:21: "Christ suffered for us, leaving you an example." But since many others who were present there suffered for Christ, and especially James, who was killed first — Acts 12:2: "And he killed James the brother of John with the sword" — why is "Follow me" said specially to Peter? The reason, according to Augustine, is that he not only suffered death for Christ, but also followed Christ in the very kind of death, namely of the cross. Matthew 16:24: "If anyone wishes to come after me, let him deny himself, take up his cross, and follow me." Or, according to Chrysostom, "Follow me" is said with respect to the office of headship; as if he were saying: just as I have from God the Father the care of the Church — Psalm 2:8: "Ask of me, and I will give you the nations for your inheritance" — so are you to be in my place over the whole Church. But why then did James have the primacy in Jerusalem after Christ's ascension? To this it must be said that he indeed had a special primacy of that particular place, whereas Peter had the universal dominion over the whole Church of the faithful. Here the commendation of John is set down, first as regards the past; second as regards the future, at the place, "When Peter therefore had seen him," etc. John is commended as regards the past by a threefold privilege. First, the privilege of Christ's special love; hence it says, "Peter, turning" — who had now begun especially and bodily to follow Jesus — "saw that disciple whom Jesus loved": in which it is given to be understood that Peter, now made a shepherd, was attending to the care of others. Luke 22:32: "And you, being once converted, confirm your brothers." Now Jesus loved John without excluding others, since above, at 15:9, he said: "As the Father has loved me, I also have loved you." But he loved him with a special love above the rest, and this for three reasons. First, on account of the keenness of his intellect; for teachers especially love intelligent disciples. Proverbs 14:35: "An intelligent servant is acceptable to the king." Second, on account of the purity of his cleanness, because he was a virgin. Proverbs 22:2: "He who loves cleanness of heart, for the grace of his lips shall have the king for his friend." Third, on account of his tender age: for we have more compassion on children and on the weak, and we show signs of familiarity, just as Christ did toward John, who turned to him while young. Hosea 11:1: "Israel was a child, and I loved him." In which it is given to be understood that God especially loves those who serve him from their youth. Micah 7:1: "My soul has desired the early figs." But against this: Proverbs 8:17: "I love those who love me." But Peter loved Christ more; above: "Do you love me more than these?" Therefore Christ ought to have loved Peter more than John. Response. It could be said that John, because more loved, was more fortunate, but Peter, because loving more, was better. But this would be against justice. And therefore this is referred to a mystery: for by these two a twofold life is signified, namely the active and the contemplative, and the end and object of both is Christ. But the active life, which is signified by Peter, loves God more than the contemplative life, which is signified by John: because it feels more the hardships of the present life, and more ardently desires to be freed from them and to go to God. But God loves the contemplative life more, because he preserves it more; for it does not end together with the life of the body, as the active life does. Psalm 86:2: "The Lord loves the gates of Sion above all the tabernacles of Jacob." But some, wishing to resolve this according to the letter, distinguish in Christ a twofold love, according to a twofold will, namely the divine and the human, and say that Christ loved Peter more with the divine love, but John more with the human love. But against this is the fact that the human will in Christ was wholly conformed to the divine will: hence whomever he loved more by the divine will, he also loved more by the human will. It must therefore be said that he loved more the one for whom he willed the greater good. Now he loved Peter more with a view to this, that he might make him more his lover; but he loved John with a view to something else, namely to keenness of intellect. Ecclesiasticus 15:5: "The Lord filled him with the spirit of wisdom and understanding." And according to this Peter is better, because charity surpasses knowledge, 1 Corinthians 13:8; but John is better as regards keenness of intellect. But to weigh their merits belongs to God alone. Proverbs 16:1: "The Lord is the weigher of spirits." And therefore others say, and better, that Peter loved Christ more in his members, and thus also was loved more by Christ, and therefore he entrusted the Church to him; but John loved Christ more in himself, and thus was loved more by him, whence he entrusted his mother to him. Or it must be said that Peter loved Christ as regards readiness and fervor, but John was more loved as regards the signs of familiarity, which Christ showed to him more on account of his youth and purity. And so consequently, when it adds, "who also leaned back at supper upon his breast," he is commended by a second privilege, namely of special familiarity with Christ; and this has been expounded above. Third, he is commended by the privilege of a special confidence which he had regarding Christ, such that he questioned him more confidently than all the others; hence it says: "and said to him: Lord, who is it that will betray you?" Which has likewise been expounded. Chrysostom said that the reason why John commemorates these privileges of his own is for the commendation of Peter. For it could be believed that Peter, because he had denied Christ, had not been admitted back to his former familiarity; and therefore, in order to exclude this, he shows that he was admitted to a greater one. He who at the supper did not dare to question, but committed the questioning to John, after the passion is entrusted with the headship over the brethren, and questions not only for himself, but for John. In which it is given to be understood that those who have fallen into sin sometimes rise again into greater grace. Baruch 4:28: "For as it was your mind to go astray from God, so, turning again, you shall seek him ten times as much." And therefore the Evangelist immediately adds, first, the question, saying: "Peter therefore, when he had seen him, said to Jesus: And what of this man?" Here the commendation of John is set down as regards the future, and first the question of Peter is set down; second, the response of Christ, at the place, "Jesus said to him: So I will have him remain till I come"; third, the understanding of this response is set down, at the place, "The saying therefore went abroad among the brethren," etc. Now it must be known, as regards the first, that when the Lord said to Peter, "Follow me," Peter began to follow him with bodily step, and John also along with him; and Peter, seeing him following, asks Christ on his behalf, saying: "And what shall this man do?" As if he were saying: behold, I follow you in the passion, but shall this man die? John also would have asked about this, but he did not dare. But according to Chrysostom, Peter did not intend to ask about the passion, but about headship. For Peter loved John above all the other fellow disciples, and they are always read to have been together, both in the Gospel and in Acts 3:1; and therefore he wished to have him as a companion in the office of preaching throughout the world: hence he says, "And what of this man" — supply: "shall he do"? Let him come with me. Consequently the response of Christ is set down, when it says: "Jesus says to him: So I will have him remain till I come." But it must be known that in the Greek it is not "so," but "if I will have him remain," etc. But it does not matter much: for however it be said, that sense of these words occurs from the outset which appeared to the apostles themselves, namely, that he does not die. For he says, "So I will have him remain till I come," as if he were saying: he will not die until my coming. But this is excluded by what is added: "and Jesus did not say, He does not die; but, So I will have him remain till I come: what is it to you?" But some, wishing to maintain this sense, say that John adds this not in order to exclude the aforesaid understanding, but in order to show that the Lord did not express this understanding through these words, but only through those, "so I will have him remain." And on account of this they say that John has not yet died. But there has been diverse opinion concerning his burial. For it is true, according to all, that he entered a tomb, and it still appears. But some say that he entered the tomb while living, and by divine power went out, translated to the place of Enoch and Elijah, where he is kept in reserve until the end of the world. And according to this it is expounded thus: "So I will have him," living, "remain," until the end of the world; and then he will suffer martyrdom for me at the hands of the Antichrist along with those two. For it is unfitting that he should not die: for whatever is born, dies. Hebrews 9:27: "It is appointed for all men once to die." But others say that he entered his tomb, which is at Ephesus, while living, and still lives in it, sleeping, until Christ comes; having as an argument for this, that there the earth wells up as if bubbling upward, which they say happens by his breathing. But Augustine excludes this, saying that it is less that he should live sleeping than that he should live in blessedness. Why then would Christ have granted, as a great gift, a long sleep to the disciple whom he loved above the rest, and deprived him of so great a good, for which the apostle desired to be dissolved and to be with Christ? Philippians 1:23. And therefore this is not to be believed; but rather that he died, and rose again even in body. And a sign of this sort is that his body is not found, and thus he remains blessed with Christ, according as he invited him. Revelation, last chapter, 20: "He who gives testimony of these things says: Surely I come quickly." It must therefore be expounded mystically, according to Augustine, so that by what he says, "remain," is understood to abide, or to wait, according to that word of Luke 24:49: "Remain in the city until you be endowed with power from on high." And thus the Lord says of John, that is, of the contemplative life: "So I will have him remain," that is, wait, "till I come," either at the end of the world, or at the death of any contemplative: because the contemplative life begun here is not brought to perfection; but, begun, it remains, and waits until Christ comes, to be perfected when he comes. Revelation 6:11: "It was said to them that they should rest for a little time yet, until the number of their fellow servants should be completed"; Luke 10:43: "Mary has chosen the best part, which shall not be taken away from her"; Proverbs 3:16: "Length of days is in her right hand, and in her left hand riches and glory." But the perfected active life, formed by the example of his passion, meanwhile follows Christ, by suffering for him. But, according to Chrysostom, it is read thus: "So I will have him remain," that is, to remain in Judea, and in this land, in order to preach; "and I will have you follow me," by having care of the whole world, and by suffering for me; and this "till I come," to destroy the Jews — "what is it to you?" As if he were saying: it is mine to ordain. For, as is found in the histories, John did not depart from Judea until the time when Vespasian, coming into Judea, took Jerusalem; and then, departing from there, he came to Asia. Or, according to Jerome: "You follow me," that is, through the passion; "and so," namely John, "I will have remain," without the passion of martyrdom and of death, "till I come" to call him to myself; above, 14:3: "I will come again, and take you to myself." "What is it to you?" Namely, concerning this privilege. Hence it is said in the legend of blessed John that when he was ninety years old, the Lord Jesus Christ appeared to him and invited him to his own banquet. Consequently, when it says, "This saying therefore went abroad among the brethren, that that disciple does not die," it is set down how the disciples understood the aforesaid words of the Lord, namely, that he would not die. And this is what it says: "the saying went abroad," that is, was made common, "among the brethren," that is, among the disciples — Psalm 132:1: "Behold how good and how pleasant it is for brethren to dwell together in unity" — "that that disciple," namely John, "does not die." But he corrects this understanding, saying: "and Jesus did not say, He does not die"; Matthew 15:16: "Are you also yet without understanding?" All the other things have been expounded.”

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“This spake he,.... These are the words of the evangelist, explaining the meaning of Christ in like manner, as in Joh 12:33 signifying by what death he should glorify God; for by the above words Christ not only intimated that Peter should die, not a natural, but a violent death, or that he should die a martyr in his cause, but the very kind of death he should die, namely, by crucifixion; and that Peter was crucified at Rome, ecclesiastical history confirms (f), when Christ was magnified, and God was glorified by his zeal and courage, faith and patience, constancy and perseverance to the end: and when he had spoken this: concerning the usage and treatment he should meet with, the sufferings he should undergo, and death he should die for his sake, for the present trial of him: he saith unto him, follow me: which may be understood literally, Jesus now rising up, and ordering him to come after him; and yet as a sign of his following him, in a spiritual sense, exercising every grace upon him, discharging every duty towards him, faithfully and constantly performing his work and office, as an apostle and preacher of the Gospel, in which he had now reinstated and confirmed him, and patiently bearing and suffering all kind of reproach, persecution, and death, for his name's sake. (f) Euseb. Eccl. Hist. l. 2. c 25.”
Source
1832
A.D.
Adam Clarke Methodist
1762–1832
“Should glorify God - Ancient writers state that, about thirty-four years after this, Peter was crucified; and that he deemed it so glorious a thing to die for Christ that he begged to be crucified with his head downwards, not considering himself worthy to die in the same posture in which his Lord did. So Eusebius, Prudentius, Chrysostom, and Augustin. See Calmet. Follow me - Whether our Lord meant by these words that Peter was to walk with him a little way for a private interview, or whether he meant that he was to imitate his example, or be conformed to him in the manner of his death, is very uncertain.”
Source
1871
A.D.
1871
“This spake he, signifying by what death he should glorify God--not, therefore, a mere prediction of the manner of his death, but of the honor to be conferred upon him by dying for his Master. And, indeed, beyond doubt, this prediction was intended to follow up his triple restoration:--"Yes, Simon, thou shall not only feed My lambs, and feed My sheep, but after a long career of such service, shalt be counted worthy to die for the name of the Lord Jesus." And when he had spoken this, he saith unto him, Follow me--By thus connecting the utterance of this prediction with the invitation to follow Him, the Evangelist would indicate the deeper sense in which the call was understood, not merely to go along with Him at that moment, but to come after Him, "taking up his cross."”
Source

Undated

date unknown
date
unknown
Glossa Ordinaria Medieval
“I will that he tarry, i. e. I will not that he suffer martyrdom, but wait for the quiet dissolution of the flesh, when I shall come and receive him into eternal blessedness.”
Modern · 1953 →

The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.