Thou hast said (συ ειπας). This is a Greek affirmative reply. Mark (Mark 14:62) has it plainly, "I am" (ειμ). But this is not all that Jesus said to Caiaphas. He claims that the day will come when Jesus will be the Judge and Caiaphas the culprit using the prophetic language in Daniel 7:13 and Psalm 109:1. It was all that Caiaphas wanted.