Vincent's NT Word Studies
16. He is risen. The he, ou=tov, is emphatic. This one. This very John.17-29. On the Peculiarities of Mark in this narrative, See Introduction.
Robertson's NT Word Studies
6:16 {John, whom I beheaded} (hon ego apekefalisa iwanen). His fears got the best of him and so Herod settled down on this nightmare. He could still see that charger containing John's head coming towards him in his dreams. The late verb apokefalizw means to cut off the head. Herod had ordered it done and recognizes his guilt.