“Then Judas, which betrayed him, answered and said, Master, is it I? He said unto him, Thou hast said.”
King James Version (KJV)
26:25 Thou hast said - That is, it is as thou hast said.
Mt 26:25 Thou hast said. In other words, "Thou art the traitor". John says that Jesus then said to Judas, "What thou doest, do quickly" and that he "immediately went out, and it was night" (Joh 13:27,30). Judas, therefore, left before the Lord's Supper was instituted.