John Chrysostom

It is therefore said, to the house of the High Priest, that nothing whatever might be done without the consent of the chief of the Priests. For thither had they all assembled waiting for Christ. Now the great zeal of Peter is manifested in his not flying when he saw all the others doing so; for it follows, But Peter followed afar off.

Catena Aurea by Aquinas ↗

Augustine of Hippo

But first He was led to Annas, the father-in-law of Caiaphas, as John says, then to Caiaphas, as Matthew says, but Mark and Luke do not give the name of the High Priest.

Catena Aurea by Aquinas ↗

Ambrose of Milan

And he followed from a distance, about to deny it; for he could not have denied it if he had joined Christ closely. But perhaps in this we should greatly admire him, that he did not leave the Lord, even when he was afraid. Fear is natural, concern is piety. He fears what is foreign: he does not flee what is his own. What he follows is devotion: what he denies is deception. What is shared is what slips away: what is of faith is what he regrets. …

Exposition Of The Gospel Of Luke 10.72 ↗

Bede

Peter, however, followed from a distance. He rightfully followed from afar, for he was already close to denying. For he could not deny if he had adhered closely to Christ. But in this, he is most worthy of our admiration, that he did not abandon the Lord even when he was afraid. For what he feared was natural; what he followed was devotion; what he denied was deception; what he repented was faith.

On the Gospel of Luke ↗