Now after this Moses and Aaron went and spoke to Pharaoh,
“Thus says the Lord God of Israel:
‘Let My people go, so they may hold a feast to Me in the desert.’”
Then Pharaoh said, “Who is He, that I should obey His voice to let Israel go?
I do not know the Lord, nor will I let Israel go.”
(Ex 5:1-2)

Let us then become lowly, that we may be high.
For most utterly does arrogance abase. This abased Pharaoh.
For, “I know not,” he says, “the Lord,” and he became inferior to flies and frogs and the locusts,
and after that with his very arms and horses was he drowned in the sea.
In direct opposition to him, Abraham says, “I am dust and ashes”
and prevailed over countless barbarians, and having fallen into the midst of Egyptians, returned,
bearing a trophy more glorious than the former,
and, cleaving to this virtue, grew ever more high. 
St. John Chrysostom