Joshua and the Angel. Rahab Helps the Israelite Spies.

5th century, with medieval and modern restorations
Nave, Basilica of Santa Maria Maggiore, Rome

The upper register portrays the visit of the "prince of the host of the Lord" to Joshua before the conquest of Jericho (Joshua 5:13-15). That he is an angel is indicated by a halo rather than wings, and his military garb expresses his role as leader of a host. In the text he has a "drawn sword," but here it is a lance or possibly a labarum a military standard, often pictured topped by a symbol in a rectangle such as the archangel Michael carries in Byzantine icons.

Seeing this person, Joshua "fell on his face to the ground." In the mosaic we see only the beginning of this movement.

The lower register illustrated Joshua 2:1-21. Joshua on the left tells his two spies to reconnoiter in Jericho. On the right, the prostitute Rahab (wearing green and standing on the battlements of the city) helps them escape by climbing down the wall.

This is part of the extensive series of Old Testament scenes portrayed in mosaics along the two walls of the nave. (To view the others, follow this link.) In most of them, events proceed chronologically from left to right and top to bottom, but in this case the spy episode, which occurs before the angel's visit, is placed below.

View this image in full resolution.
Read more about Joshua..

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