Luke 22:50

For Peter being well versed in the law, and full of ardent affection, knowing that it was counted righteousness in Phineas that he had killed the sacrilegious persons, struck the High Priest's servant. The Lord in wiping away the bloody wounds, conveyed thereby a divine mystery, namely, that the servant of the prince of this world, not by the condition of His nature but by guilt, should receive a wound on the ear, for that he had not heard the words of wisdom. Or, by Peter so willingly striking the ear, he taught that he ought not to have a ear outwardly, who had not one in a mystery. But why did Peter do this? Because he especially obtained the power of binding and loosing; therefore by his spiritual sword he takes away the interior ear of him who understandeth not. But the Lord Himself restores the hearing, showing that even they, if they would turn, might be saved, who inflicted the wounds in our Lord's Passion; for that all sin may be washed away in the mysteries of faith.

He who struck, according to John, was Peter, but he whom he struck was called Malchus.

Or that servant is the Jewish people sold by the High Priests to an unlawful obligation, who, by the Passion of our Lord, lost their right ear; that is, the spiritual understanding of the law. And this ear indeed is cut off by Peter's sword, not that he takes away the sense of understanding from those that hear, but manifests it withdrawn by the judgment of God from the careless. But the same right ear in those who among the same people have believed, is restored by the Divine condescension to its former office.

The disciples are inflamed with zeal, and unsheath their swords. But whence have they swords? Because they had slain the lamb, and had departed from the feast. Now the other disciples ask whether they should strike; but Peter, always fervent in defence of his Master, waits not for permission, but straightway strikes the servant of the High Priest; as it follows, And one of them smote, &c.

(de Con. Ev. lib. iii. c. 5.) Now Luke says, But Jesus answered and said, Suffer ye thus far; which is what Matthew records, Put thy sword up into its sheath. Nor will it move you as contrary thereto, that Luke says here that our Lord answered, Suffer ye thus far, as if He had so spoken after the blow to show that what was done had pleased Him so far, but He did not wish it to proceed farther, seeing that in these words which Matthew has given, it may rather be implied that the whole circumstance in which Peter used the sword was displeasing to our Lord. For the truth is, that upon their asking, Lord, shall we strike with the sword? He then answered, Suffer ye thus far, that is, be not troubled with what is about to happen. They must be permitted to advance so far, that is, to take Me, and so to fulfil the things which were written of Me. For he would not say, And Jesus answering, unless He answered this question, not Peter's deed. But between the delay of their words of question to our Lord and His answer, Peter in the eagerness of defence struck the blow. And two things cannot be said, though one may be said and another may be done, at the same time. Then, as Luke says, He healed him who was struck, as it follows, And he touched his ear, and healed him.