3 “Pilate therefore said unto Him, Are you a king then? Jesus answered, You say that I am a king.” Not that He was afraid to confess Himself a king, but “You say” has been so balanced that He neither denies Himself to be a king (for He is a king whose kingdom is not of this world), nor does He confess that He is such a king as to warrant the supposition that His kingdom is of this world. For as this was the very idea in Pilate's mind when he said, “Are you a king then?” so the answer he got was, “You say that I am a king.” For it was said, “You say,” as if it had been said, Carnal yourself, you say it carnally.
Source: Tractates on the Gospel of John (New Advent)