John Chrysostom

Wherefore hath he reminded us of that reclining? Not without cause or in a chance way, but to show us what boldness Peter had after the denial. For he who then did not dare to question Jesus, but committed the office to another, was even entrusted with the chief authority over the brethren, and not only doth not commit to another what relates to himself, but himself now puts a question to his Master concerning another. John is silent, but Peter speaks. …

Homily on the Gospel of John 88 ↗

Theophylact of Ohrid

Why does the evangelist mention that he leaned on His breast and asked, "Who is it that will betray You?" Not simply or by chance, but to show that Peter, even after his denial, had boldness before the Lord. For he who before the Cross did not dare to ask about the betrayer, but entrusted the question to another, namely John, is now entrusted with the care of all, and not only does he not entrust the question about himself to another, but even concerning that very disciple who enjoyed a special love above all the others, he asks the …

Commentary on John ↗

Augustine of Hippo

He calls himself the disciple whom Jesus loved, because Jesus had a greater and more familiar love for him, than for the rest; so that He made him lie on His breast at supper. In this way John the more commends the divine excellency of that Gospel which he preached. Some think, and they no contemptible commentators upon Scripture, that the reason why John was loved more than the rest, was, because he had lived in perfect chastity from his youth up. …

Catena Aurea by Aquinas ↗

Thomas Aquinas

Now we see that John is commended: first, as to his past; then with respect to his future (v 21). John is commended on three points in his past. First, John had the privilege of having Christ's special love. The Evangelist says, Peter turned, for he had begun to follow Jesus even bodily, and saw following them the disciple whom Jesus loved. Here we see that Peter, already made a shepherd, was intent on the care of others: "And when you have turned again, strengthen your brethren" (Lk 22:32). …

Commentary on John ↗

Bonaventure

It is asked about what he says: That disciple whom Jesus loved. How did he dare to say this, when it is said in Ecclesiastes nine: No one knows whether he is worthy of love or of hatred? Likewise, since Christ loved all, why did John attribute this to himself, namely that he was loved more? This seems false: because Peter loved more; therefore he was better; but God loves the better more; therefore he loved Peter more than John. To this it can be answered that John knew by revelation or by certain signs that he was loved. …

Commentary on John, Chapter 21 ↗