And Moses and Aaron went in unto Pharaoh, and they did so as the LORD had commanded: and Aaron cast down his rod before Pharaoh, and before his servants, and it became a serpent.
All Commentaries on Exodus 7:10 Go To Exodus 7
Ephrem The Syrian
AD 373
The staff is a sign of the cross. It caused all the plagues when it swallowed the snakes, just as [the cross] would destroy all idols. With [the staff], [Moses] divided the sea and drowned the Egyptians. That prefigured the destruction of the Canaanites.