When it was evening, he took his place with the twelve; and while they were eating, he said, “Truly I tell you, one of you will betray me.” And they became greatly distressed and began to say to him one after another, “Surely not I, Lord?” He answered, “The one who has dipped his hand into the bowl with me will betray me. The Son of Man goes as it is written of him, but woe to that one by whom the Son of Man is betrayed! It would have been better for that one not to have been born.” Judas, who betrayed him, said, “Surely not I, Rabbi?” He replied, “You have said so.”
Notice here how they all call Jesus “Lord”, whereas Judas calls Jesus “Rabbi”, or Teacher. To the original Jewish audience here, this would have been noticed and significant. But don’t mistake this. This isn’t some Evangelical emphasis of seeing Jesus as “Lord of your life” and not “just” a teacher.
Rather, the difference is in seeing things in the new order versus the old one. It’s probably significant that Matthew us the Jewish term “Rabbi” and not just the normal Greek word for “teacher”. To follow a rabbi was still intense and genuine discipleship, not some “lesser devotion”. The point is that Judas still didn’t “get it”. Therefore, Jesus points out how this ultimately condemns him.