So that disciple, leaning back against Jesus, said to him, “Lord, who is it?”
We have here the discovery of Judas's plot to betray his Master. Christ knew it from the beginning; but now first he discovered it to his disciples, who did not expect Christ should be betrayed, though he had often told them so, much less did they suspect that one of them should do it. Now here, I.
Commenting on John 13:18-30
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.
Verse 25. He then lying on Jesus' breast. This a different word from the one rendered leaning. It means falling back or laid his head back on the bosom of Jesus, so that he could speak to him privately without being heard by the others.