John 13:25

25 and that one having leant back on the breast of Jesus, respondeth to him, `Sir, who is it?'

John 13:25 Meaning and Commentary

John 13:25

He then lying on Jesus' breast
Being on the couch just before Jesus, with his back to him, he bends backwards, and falling on Jesus' breast, whispers in his ear:

and saith unto him, Lord, who is it?
using his interest in Christ, and making thus free with him, in compliance with Peter's request; and was no doubt desirous himself of knowing who the person was.

John 13:25 In-Context

23 And there was one of his disciples reclining (at meat) in the bosom of Jesus, whom Jesus was loving;
24 Simon Peter, then, doth beckon to this one, to inquire who he may be concerning whom he speaketh,
25 and that one having leant back on the breast of Jesus, respondeth to him, `Sir, who is it?'
26 Jesus answereth, `That one it is to whom I, having dipped the morsel, shall give it;' and having dipped the morsel, he giveth [it] to Judas of Simon, Iscariot.
27 And after the morsel, then the Adversary entered into that one, Jesus, therefore, saith to him, `What thou dost -- do quickly;'
Young's Literal Translation is in the public domain.