John Calvin Commentary John 21:17

"He saith unto him the third time, Simon, [son] of John, lovest thou me? Peter was grieved because he said unto him the third time, Lovest thou me? And he said unto him, Lord, thou knowest all things; thou knowest that I love thee. Jesus saith unto him, Feed my sheep." — John 21:17 (ASV)

Peter was grieved. Peter undoubtedly did not understand Christ's purpose in asking the same question so often; and therefore he thinks that he is indirectly accused, as if he had not answered with sincerity. But we have already shown that the repetition was not unnecessary.

Besides, Peter was not yet sufficiently aware how deeply the love of Christ must be engraved on the hearts of those who must struggle against countless difficulties. He later learned by long experience that such a trial had not been made in vain.

Those who are to undertake the responsibility of leading the Church are also taught, through his example, not to examine themselves superficially, but to thoroughly scrutinize what zeal they possess, so that they do not shrink back or lose heart in the middle of their course.

We are also taught that we should patiently and gently submit if at any time the Lord subjects us to a severe trial, because He has good reasons for doing so, even though His reasons are usually unknown to us.