Miracle of the Rock. – The miracle performed by Moses in the desert was soon represented in early Christian funerary art; the patriarch strikes the rock of Horeb and from it gushes forth water that quenches the thirst of the people of Israel (Ex. 17:5). Already St Paul teaches that Petra autem erat Christus (I Cor. 10:4).
This concept is then widely developed in ancient Christian literature; from St Irenaeus, who sees in the water the rivers of the Holy Spirit to be poured out upon the chosen people (Adv. Haer., 4, 33, 19; PG 7, 1082), to St Cyprian, who affirms that “if the Jews thirst and seek Christ, they will be refreshed among us, obtaining the grace of Baptism” (Ep. 63, 8; CSEL 2, p. 706). The representation, therefore, of the miracle of the rock is a symbol of Baptism and is already found in the cycle of the so-called Greek Chapel in the cemetery of Priscilla (Wilpert, Pitture, pl. 13); it recurs in the cemeteries of Callisto, Domitilla, Praetextatus, Giordani, in the cemetery with a single laurel, etc., and outside Rome also in the cemetery known as that of St Januarius of the Poor in Naples. Moses is always represented in tunic and pallium, with the virga virtutis, beardless in the earliest period; in a cubiculum of the cemetery of the Giordani the scene is instead set between two trees rather than in the desert (E. Josi, Le pitture virginali nel cimitero dei Giordani, in Rivista di archeologia cristiana, 5 [1928], pp. 188-89, fig. 3).
The scene is also found scratched on a sepulchral slab from the cemetery of Cyriaca (O. Marucchi, Monumenti del Museo Pio Lateranense, Milan 1910, pl. 57, no. 14), on gold-glass vessels, on ivory plaques, on one of the wooden panels of the door of S. Sabina, on bronze fittings, on a fabric from Almin now in the Museum für Kunst und Industrie in Vienna, etc.
In a late sarcophagus from Aix there is a group of people quenching their thirst (Wilpert, Sarcofagi, pl. 97, 2).
A glass cup of the 5th century discovered at Podgoritza (Albania) offers a rough depiction of the miracle of the rock with the legend: “Petrus virga percussit fontes coeperunt curere.” Peter thus takes the place of Moses; indeed, already on sarcophagus 19 of the Lateran Museum, from the Vatican Basilica, the iconographic type of St Peter is recognized, and those quenching their thirst at the rock are three young men in military dress (Wilpert, Sarcofagi, pl. 9); a similar costume is worn by one who quenches his thirst in a scene of the same miracle in the cubiculum known as that of the Sheep in the cemetery of Callisto (Wilpert, Pitture, pl. 237). Wilpert interpreted this scene, which recurs so frequently in the sarcophagi of Rome, Gaul and Spain, as a representation of the Baptism conferred by St Peter on the centurion Cornelius and his household.
The scene is repeated also on a bronze lamp in the Archaeological Museum of Florence (W. Neuss, Die Kunst der alten Christen, Augsburg 1926, pl. 92, fig. 184).