The earliest known version of the
standard depiction is in an apse mosaic at Saint Catherine's Monastery, Mount
Sinai dating to the period of (and probably commissioned by) Justinian the
Great, where the subject had a special association with the site, because of
the meeting of Christ and Moses, "the 'cult hero' of Mount Sinai".
This very rare survivor of Byzantine art from before the Byzantine iconoclasm
shows a standing Christ in a mandorla with a cruciform halo, flanked by
standing figures of Moses on the left with a long beard, and Elijah on the
right. Below them are the three disciples named as present in the Synoptic
Gospels: Saints Peter, James, son of Zebedee and John the Evangelist ■