Ante-Nicene Fathers, Vol IX:
Epistle to Gregory and Origen's Commentary on the Gospel of John.: Chapter XXIX

29.  The River of Egypt and Its Dragon, Contrasted with the Jordan.

But that the Spirit in the inspired Scriptures is not speaking mainly of rivers to be seen with the eyes, may be gathered from Ezekiel’s prophecies against Pharaoh, king of Egypt: 4947   “Behold I am against thee, Pharaoh, king of Egypt, the great dragon, seated in the midst of rivers, who sayest, Mine are the rivers, and I made them.  And I will put traps in thy jaws, and I will make the fishes of the river to stick to thy fins, and I will bring thee up from the midst of thy river, and all the fish of the river, and I will cast thee down quickly and all the fish of the river; thou shalt fall upon the face of thy land, and thou shalt not be gathered together, and thou shalt not be adorned.”  For what real bodily dragon has ever been reported as having been seen in the material river of Egypt?  But consider if the river of Egypt be not the dwelling of the dragon who is our enemy, who was not even able to kill the child Moses.  But as the dragon is in the river of Egypt, so is God in the river which makes glad the city of God; for the Father is in the Son.  Hence those who come to wash themselves in Him put away the reproach of Egypt, and become more fit to be restored.  They are cleansed from that foulest leprosy, receive a double portion of spiritual gifts, and are made ready to receive the Holy Spirit, since the spiritual dove does not light on any other stream.  Thus we have considered in a way more worthy of the sacred p. 375 subject the Jordan and the purification that is in it, and Jesus being washed in it, and the house of preparation.  Let us, then, draw from the river as much help as we require.

Footnotes

Ezek. 29.3-5.