Plaque with Moses, Aaron, and the Brazen Serpent

Circa 1200
Metropolitan Museum of Art, 17.190.439. Gift of J. Pierpont Morgan.
From Cologne
Champlevé enamel on gilded copper.

The incident pictured is in Numbers 21:4-9. This passage does not mention Aaron: God tells Moses to put up a pole with a bronze serpent at the top; those who gaze on it will be cured of the bite of a certain serpent. Thus, one would expect the figure pointing to the serpent would be Moses. But is the thing on his head a pair of horns, conventionally an attribute of this prophet, or are the horns part of the headpiece usually shown on Aaron?

More of Aaron
More of Moses

Photographed at the museum by Richard Stracke, shared under Attribution-NonCommercial-ShareAlike license.