Note the importance of the medallions
Indicating events in the life of Saint John,
Including his martyrdom at lower left. Dove of Holy Spirit, lowered to him by the Hand of God, whispering in his ear, Ink provided to him by a monk at right. Idea of Crossing the borders, from one realm to another. From heavenly inspiration to the Writer of the book, to the reality of the monk
Who transcribes the words.