A.T. Robertson Commentary John 13:37

"Peter saith unto him, Lord, why cannot I follow thee even now? I will lay down my life for thee." — John 13:37 (ASV)

"Why can I not follow thee even now?" (δια τ ου δυναμα σο ακολουθειν αρτι; ). The use of αρτ (right now, this minute) instead of νυν (at this time, verse 36) illustrates the impatience of Peter.

I will lay down my life for thee (τεν ψυχην μου υπερ σου θησω). Future active indicative of τιθημ. Peter, like the rest, had not yet grasped the idea of the death of Christ, but, like Thomas (11:16), he is not afraid of danger. He had heard Christ's words about the good shepherd (10:11) and knew that such loyalty was the mark of a good disciple.