Mathias Grünewald
The Isenheim Altarpiece: Open state, left wing

1512-1516
Unterlinden Museum, Colmar, France

St. Paul, oldest of the Christian hermits, is visited by St. Anthony Abbot. Above left is the raven that brings Paul a loaf of bread every day. At their feet are some of the plants that friars of the Antonine order use to treat victims of erysipelas.

Read more about St. Anthony Abbot.
Read more about St. Paul the Hermit.

Source: this page at Wikimedia Commons.