Adam Clarke on Matthew 26:25

Judas - said, Master, is it I? - What excessive impudence! He knew, in his conscience, that he had already betrayed his Master, and was waiting now for the servants of the chief priests, that he might deliver him into their hands; and yet he says, (hoping that he had transacted his business so privately that it had not yet transpired), Master, is it I? It is worthy of remark, that each of the other disciples said κυριε, Lord, is it I? But Judas dares not, or will not, use this august title, but simply says ραββι, Teacher, is it I?

Thou hast said - Συ ειπας, or אתון אמריתון atun amaritun, "Ye have said," was a common form of expression for Yes. It Is so. "When the Zipporenses inquired whether Rabbi Judas was dead? the son of Kaphra answered, Ye have said," i.e. He is dead. See Schoettgen. Hor. Hebr. p.