On Peter’s denials, comp. Notes on Matthew 26:69-75, and see in this Gospel John 13:38.
Art not thou also one of this man’s disciples? — i.e., “Thou as well as thy friend, whom I know.” There is no charge brought against him. The words are apparently simply words of recognition, or as furnishing a reason for admitting him with his friend, but Peter is conscious that he had attempted to kill, and had succeeded in wounding, one of the high priest’s servants. He therefore dreads this recognition.