Charles Ellicott Commentary John 13:36

"Simon Peter saith unto him, Lord, whither goest thou? Jesus answered, Whither I go, thou canst not follow now; but thou shalt follow afterwards." — John 13:36 (ASV)

Simon Peter said unto him, Lord, whither goest thou?—Compare to John 13:33. The earnest, loving nature of the Apostle dwells upon the words which tell of the Master’s departure. He is prepared to follow Him to danger, or even to death, and, so that he may do so, asks where He is going.

Whither I go, thou canst not follow me now.—Our Lord does not give the answer which Saint Peter had sought, but repeats the statement of John 13:33. For Saint Peter, as for the others, the place must be prepared and the way opened before they could follow (John 14:2). For him, as for his Master, the day’s work was to be done before the night would come, and it was not done yet. But that night would come, and he would afterward follow his Master in a more literal sense than any of which he thought. (See Notes on John 21:18-19.)