<Li> Judas Iscariot, Peter, and John form another group of three . </Li> <P> Judas is wearing green and blue and is in shadow, looking rather withdrawn and taken aback by the sudden revelation of his plan . He is clutching a small bag, perhaps signifying the silver given to him as payment to betray Jesus, or perhaps a reference to his role within the 12 disciples as treasurer . He is also tipping over the salt cellar . This may be related to the near - Eastern expression to "betray the salt" meaning to betray one's Master . He is the only person to have his elbow on the table and his head is also horizontally the lowest of anyone in the painting . </P> <P> Peter looks angry and is holding a knife pointed away from Christ, perhaps foreshadowing his violent reaction in Gethsemane during Jesus' arrest . </P> <P> The youngest apostle, John, appears to swoon . </P>

Who's holding the knife in the last supper