And again he denied with an oath,.... He denied a second time, that he had ever been with Jesus, or was a disciple of his; and to put it out of all doubt, and an end to all dispute about it, and further charge of this kind, as he hoped, he annexed an oath to it: he swore by the God of truth; made a solemn appeal to the omniscient God, the searcher of hearts, that he was so far from being ever with Jesus of Nazareth, or a disciple of his, that, says he,I do not know the man: meaning not only that he had no personal knowledge of him, or acquaintance with him; but that he had never seen the man in his life, nor did he know what manner of man he was.
This, as it was a downright falsehood, it was what he had no need to have said; for there were multitudes that knew Christ in this sense, who never joined with him, or became his disciples. This was so much overdoing it, that it was much it had not given them a suspicion of him.
Those that would excuse Peter's sin, by supposing that he meant, that he knew Christ to be God, and did not know him as a mere man, have no foundation for such a supposition; and indeed, such an ambiguous expression, and mental reservation, is no other than dealing fallaciously.
Peter knew Christ in every sense; he knew him spiritually, whom to know is life eternal: and he valued the knowledge of him above all things else: he knew him to be God, and the Son of God; he knew him as mediator, and the Saviour of lost sinners; he knew him as man, and had had personal intimacy and conversation with him of a long time, and yet now denies he knew him; and that with an oath, adding perjury to lying; and so it is, that one sin leads on to another.