Adam Clarke on John 13:25

He then lying on Jesus' breast - Επιπεσων, laying his head against the breast of Christ, in a loving, respectful manner. As the expressions in the text are different here from those in the preceding verse, it shows that John altered his position at table, in order to ask the question which Peter suggested, which he probably did by whispering to our Lord; for, from Joh 13:28, we may learn that the other disciples had not heard what John said; and it is likely that the following words - It is he to whom I shall give the morsel when I have dipped it, were whispered back by Christ to John.