“Now when the even was come, he sat down with the twelve.And as they did eat, he said, Verily I say unto you, that one of you shall betray me. And they were exceeding sorrowful, and began every one of them to say unto him, Lord, is it I?… Then Judas, which betrayed him, answered and said, Master, is it I? He said unto him, Thou hast said.”
Why does Jesus say “Thou hast said” in response to Judas (and Pontius Pilate too) asking a question? It makes more sense for him to say “thou hast said” in response to them, well, saying it – affirming that it is he (Judas) who would betray Christ.
I think the answer is in the Greek.
An alternate translation (and better in this context) of εἶπεν Μήτι ἐγώ εἰμι ῥαββί would be:
“Judas said, “Master, it is I…is it not? He said unto him, Thou hast said.”
Judas said “It is I…” that’s why Jesus can respond “Thou hast said it.”
English questions flip word order “Is it i?” vs. “It is I” which makes these little moments from our Lord less comprehensible. When Pontius Pilate says, “You are the king of the Jews…?” Jesus says, “You said it.”
The question is formulated as a declarative statement, to which Jesus replies, “Thou hast said.”