Charles Spurgeon Commentary Exodus 14:5

"And it was told the king of Egypt that the people were fled: and the heart of Pharaoh and of his servants was changed towards the people, and they said, What is this we have done, that we have let Israel go from serving us?" — Exodus 14:5 (ASV)

Nothing but the grace of God will truly humble people. These Egyptians had been crushed by terrible plagues into a false kind of humility, but they were soon as proud as ever. Nothing but the omnipotent grace of God can really subdue a proud and stubborn heart.