Will I not deny thee - Will not deny my connection with thee, or that I knew thee.
"All" the disciples said the same thing, and all fled at the approach of danger, "forsaking" their Master and Friend, and practically denying that they knew him, Matthew 26:56.

Though I should die with thee, yet will I not deny thee - He does not take the warning which his Lord gave him - he trusts in the warm, sincere attachment to Christ which he now feels, not considering that this must speedily fail, unless supported by the power of God.

Peter saith unto him,.... Mark says, "he spake the more vehemently", Mark 14:31; his spirits were raised to a greater pitch of resentment, and he expressed himself in stronger terms, and in more peremptory and self-confident language,
though I should die with thee, yet will I not deny thee: he seems to have understood Christ, that he should suffer death, and that he would be in great danger himself, and therefore rather than lose his life would deny his master; wherefore he most confidently affirms, that should this be the case, should he be called to suffer death for his sake, or along with him, he would most cheerfully embrace it, rather than be guilty of so dreadful a crime, which he could not look upon but with the utmost detestation and abhorrence, as to deny his dear Lord and Saviour:
likewise also said all the disciples; that they would never be offended because of him, and would die with him rather than deny him. This they said, being also self-confident and ignorant of their own weakness, and drawn into these expressions through Peter's example; and that partly to show their equal abhorrence of so horrible an iniquity, as denying Jesus; and partly to remove all suspicion from them, lest they should be thought to have less love and zeal for Christ than Peter had.

In like manner also said all the disciples - But such was the tenderness of our Lord, that he would not aggravate their sin by making any reply.