A.T. Robertson Commentary John 13:24

"Simon Peter therefore beckoneth to him, and saith unto him, Tell [us] who it is of whom he speaketh." — John 13:24 (ASV)

Beckoneth (νευε). Old verb to nod, in N.T. only here and Ac 24:10. They were all looking in surprise at each other.

Tell us who it is of whom he speaketh (ειπε τις εστιν περ ου λεγε). Second aorist active imperative with indirect question (τις) and relative clause (περ ου). Peter was cautious, but could not contain his curiosity. John in front of Jesus was in a favourable position to have a whispered word with him.

Breast (στηθος). As in 21:20; Luke 18:13 in place of κολπον (verse 23). This is the moment represented in Leonardo da Vinci's "Last Supper," only he shows the figures like the monks for whom he painted it.