SCRIPTURE COMMENTARY #535
And apprehending Jesus, they led him to the high priest's house. But Peter followed afar off. And when they had kindled a fire in the midst of the hall and were sitting about it, Peter was in the midst of them. Whom when a certain servant maid had seen sitting at the light and had earnestly beheld him, she said: This man also was with him. But he denied him, saying: "Woman, I know him not." And after a little while, another seeing him, said: "Thou also art one of them." But Peter said: "O man, I am not." And after the space, as it were of one hour, another certain man affirmed, saying: "Of a truth, this man was also with him: for he is also a Galilean." And Peter said: "Man, I know not what thou sayest." And immediately, as he was yet speaking, the cock crew. And the Lord turning looked on Peter. And Peter remembered the word of the Lord, as he had said: "Before the cock crow, thou shalt deny thrice." And Peter going out, wept bitterly. (Luke 22:54-62)
DIVINE WISDOM PERMITTED PETER'S FALL: 1. so that Peter might become very humble, and, as the vicar of the Good Shepherd, might be gentle and considerate to those under his charge; 2. that all men might learn to know the mercy of God and the power of grace, and that no sinner might give himself up to despair.
[From 'A Practical Commentary on Holy Scripture' by Bishop Knecht, D.D.]
(1899 Douay-Rheims Bible)