“To those who keep their mind unstained by the world and from an empty preoccupation with the things of this life, it does seem that Christ reveals his own peculiar glory by a subtle and perhaps incomprehensible process, thereby showing also the glory of the Father, which must be what Jesus meant when he said, “Whoever has seen me has seen the Father.”
Cyril of Alexandria (c.376-444) in Commentary on the Gospel of John 9, IVb.