A.T. Robertson Commentary Mark 15:9

"And Pilate answered them, saying, Will ye that I release unto you the King of the Jews?" — Mark 15:9 (ASV)

The King of the Jews (τον βασιλεα των Ιουδαιων). That phrase from this charge sharpened the contrast between Jesus and Barabbas which is bluntly put in Mt 27:17 "Barabbas or Jesus which is called Christ." See discussion there.