John 18:34

The Synoptics reported that Jesus replied, "It is as you say" (Gr. sy legeis, Matthew 27:11; Mark 15:2; Luke 23:3). John also recorded that Jesus gave that answer (John 18:37), but he included additional conversation first. This added material included Jesus’ explanation of the nature of His kingship (John 18:36).

Jesus asked Pilate His question to determine how He would answer him. If his question had arisen from his own understanding and curiosity, Jesus presumably would have dealt with Him as a sincere inquirer. If he was merely trying to clarify the essence of the Sanhedrin’s charge, Jesus would need to answer differently. If Pilate meant, "Are you a political king conspiring against Caesar?" the answer would have been, "No." If he meant, "Are you the messianic king of Israel?" the answer would have been, "Yes." The object of interrogation, Jesus, became the interrogator temporarily. The fact that Jesus questioned Pilate at all was pure grace in that it allowed Pilate to explain his motivation and possibly reduce his culpability.