This is the disciple which testifieth of these things, and wrote these things. — Comp. John 20:30-31. As we have there the formal close of what seems to have been the original Gospel, we have here the formal close of the epilogue. The words are, however, too wide to be limited to the epilogue, and clearly refer to all that has preceded. They identify the writer with the disciple just mentioned, i.e., the disciple whom Jesus loved, and the form of the sentence implies that he who wrote these things was still living, and bearing witness to their truth. He is still testifying to the things of which he wrote.
And we know that his testimony is true. — Our first and natural thought is that these are not the words of the writer of the Gospel, but the additional witness of persons knowing him and testifying to his writing. It is usual to explain the “we know” by referring to 1 John 5:18-20; but the plural of a letter ought not to be quoted to explain the plural in an historic document, and it is probable that the natural thought is the true one. But though the words are an addition, they are a contemporaneous addition present in every important MS. and version, and an undoubted part of the original text. We cannot tell who are the persons whose words we here read — Andrew it may be, or Philip, or some of the seventy disciples who had been witnesses of the work of Christ, or some of the Ephesian Church, as Aristion or John the Presbyter, who felt that the Apostle’s personal character gave the stamp of truth to all he said, and add here the conviction that all these words were true. (Comp. Introduction, p. 377.)