Grandes chroniques de France Jean Fouquet: Caligula Baptist, illuminated manuscript

The Naming of St John the Baptist, in the Caligula Troper, Cotton MS Caligula A XIV;
British Library, [1]:

The feast of John the Baptist begins with a depiction of his naming, a subject known in a few other Anglo-Saxon works and one appropriate to a troper because of its reference to the voice. Elizabeth, whose neighbours believe the child should be named for his father, holds her gold-swathed infant and insistently raises her index finger in speech. Zacharias, her husband who had been struck mute because of his disbelief at his aged wife's pregnancy, asserts her wish by writing in Latin on a wax tablet, "His name is John."