VINCENZO PIROZZI/AKG-IMAGES

MOSES OR PETER? In Exodus 17:6, Moses strikes the rock to provide drinking water for his fellow Israelites during their wanderings to the Promised Land. Wearing Roman military cloaks and headgear, however, the two figures drawing water might rather be Roman soldiers. The scene would then illustrate an apocryphal legend about St. Peter, who during his detention in Rome miraculously opened a spring of water, which he then used to baptize his two jailers. Painted in the catacomb of Commodilla near the Via Ostiensis, in Rome, this scene dates to c. 365.