Notebooks of Leonardo Da Vinci
(Translated by Jean Paul Richter, 1888)
"Notes on the Last Supper"
I.665.  Another speaks into his neighbour's* ear and he, as he listens to him, turns towards him to lend an ear , while he holds a knife in one hand, and in the other the loaf half cut through by the knife.  Another who has turned, holding a knife in his hand, upsets with his hand a glass on the table .
[*masculine in Florentine Italian]
[Richter's footnote to 665: The various actions described in lines 9-10, 13-14 are to be seen in the group of Peter, John and Judas; in the finished picture however it is not a glass but a salt cellar that Judas is upsetting.]