At this, the servant girl watching the door said to Peter, “Aren’t you also one of this man’s disciples?” “I am not,” he answered.
17. Then the maid that kept the door said to Peter. Peter is introduced into the high priest’s hall; but it cost him very dear, for, as soon as he sets his foot within it, he is constrained to deny Christ. When he stumbles so shamefully at the first step, the foolishness of his boasting is exposed.
We have here an account of Christ's arraignment before the high priest, and some circumstances that occurred therein which were omitted by the other evangelists; and Peter's denying him, which the other evangelists had given the story of entire by itself, is interwoven with the other passages.
Commenting on John 18:13-27
Then saith the damsel that kept the door unto Peter,.... She being relieved, either by her father, if porter, or by a fellow servant, had the opportunity of coming into the hall, where Peter was, and was curious to observe him, who he should be, that that person of note should order him to be admitted, when an affair of so much privacy and importance...