Luke 22:61

Lastly, those whom Jesus looks upon weep for their sins. Hence it follows, And Peter remembered the word of the Lord, how he had said to him, Before the cock crow, thou shalt deny me thrice. And he went out, and wept bitterly. Why did he weep? Because he sinned as man. I read of his tears, I do not read of his confession. Tears wash away an offence which it is shame to confess in words. The first and second time he denied and wept not, for as yet our Lord had not looked upon him. He denied the third time, Jesus looked upon him, and he wept bitterly. So then if thou wilt obtain pardon, wash away thy guilt in tears.

(Hom. 83. in Joan.) Marvel now at the case of the Master, who though He was a prisoner, had exercised much forethought for His disciple, whom by a look He brought to Himself, and provoked to tears; for it follows, And the Lord turned, and looked upon Peter.

How we should understand this, requires some careful consideration; for Matthew says, Peter was sitting without in the hall, which he would not have said unless the transaction relating to our Lord were passing within. Likewise also, where Mark said, And as Peter was beneath in the hall, he shows that the things he had been speaking of took place not only within but in the upper part. How then did our Lord look upon Peter? not with His bodily face, since Peter was without in the hall among those who were warming themselves, while these things were going on in the inner part of the house. Wherefore, that looking upon Peter seems to me to have been done in a divine manner. And as it was said, Look thou, and hear me, (Ps. 13:3.) and, Turn and deliver my soul, (Ps. 6:4.) so I think the expression here used, The Lord turned and looked upon Peter.

For to look upon him is to have compassion, seeing that not only while penance is being practised, but that it may be practised, the mercy of God is necessary.