John 13:36

(Hom. lxxiii. 3) Great is love, and stronger than fire; nothing can stop its course. Peter the most ardent of all, as soon as he hears our Lord say, Whither I go ye cannot follow Me now, asks, Lord, whither goest Thou?

A great thing is love, and stronger than fire itself, and it goeth up to the very heaven; there is no hindrance which can restrain its tearing force. And so the most fervent Peter, when he hears, "Whither I go ye cannot come," what saith he? "Lord, whither goest thou?" and this he said, not so much from wish to learn, as from desire to follow. To say openly, "I go," he dared not yet, but, "Whither goest thou?" Christ answered, not to his words, but to his thoughts. For that this was his wish, is clear from what Christ said, "Whither I go thou canst not follow Me now." Seest thou that he longed for the following Him, and therefore asked the question? And when he heard, "thou shalt follow Me afterwards" not even so did he restrain his longing, and, though he had gained good hopes, he is so eager as to say, "Why cannot I follow Thee now? I will lay down my life for Thee."

(Tr. lxvi. 1) The disciple asks this, as if he were ready to follow. But our Lord saw his heart; Jesus answered him, Whither I go, thou canst not follow Me now; He checks his forwardness, but does not destroy his hope; nay, confirms it; But thou shalt follow Me afterwards. Why hastenest thou, Peter? The Rock has not yet established thee with His spirit. Be not lifted up with presumptions, thou canst not now; be not cast down with despair, thou shalt follow Me afterwards.

While the Lord Jesus was commending to the disciples that holy love wherewith they should love one another, "Simon Peter saith unto Him, Lord, whither goest Thou?" So, at all events, said the disciple to his Master, the servant to his Lord, as one who was prepared to follow. Just as for the same reason the Lord, who read in his mind the purpose of such a question, made him this reply: "Whither I go, thou canst not follow me now;" as if He said, In reference to the object of thy asking, thou canst not now. He does not say, Thou canst not; but "Thou canst not now." He intimated delay, without depriving of hope; and that same hope, which He took not away, but rather bestowed, in His next words He confirmed, by proceeding to say, "Thou shall follow me afterwards." Why such haste, Peter? The Rock (petra) has not yet solidified thee by His Spirit. Be not lifted up with presumption, "Thou canst not now;" be not cast now into despair, "Thou shalt follow afterwards."