Christ here is Christ the Teacher: the gesture of Christ's right hand is not the gesture of blessing, but the orator's gesture; the identical gesture is to be seen in a panel from an ivory diptych of an enthroned vice-prefect, a Rufius Probianus, ca 400, of which Peter Brown remarks, "With his hand he makes the 'orator's gesture' which indicates that he is speaking, or that he has the right to speak."