Following the detailed texts of his apocryphal Acts [of Peter], Peter [the Apostle] had a strong disagreement with an illustrious Palestinian, Simon Magus. Two moments of this dispute are illustrated at Monreale: the dispute that occurred before the emperor Nero and the failure by Simon Magus to show spiritual power.
The two inscriptions say: Here in Rome, before Nero, Peter and Paul disputed with Simon Magus. Here, under the command of Peter, as Paul was praying, Simon Magus fell to the ground.
In the second scene, as Peter is speaking out against Simon Magus, with the usual Byzantine gesture of speaking [and not “blessing” as is often generally said by many nowadays], Paul is depicted as praying, on his knees with the palms of his hands facing upwards.