"Yet Pharaoh’s heart was hardened, and he did not listen to them (Moses and Aaron), as the Lord had said." (v.13)
In our passage, the Pharaoh's heart was too hard for the signs (rod/snake v.12 and river of blood v.20) to make much of an impression on it. He did not see that Moses had done much more than his own magicians could do and ignored the request of God.
This self-willed, obstinate man who persistently hardened himself against God, and resisted His all warnings (the ten plaques) would eventually choose to loose his first born son before giving into God’s request, to let His people go.
Even today there are those who would rather harden their hearts and deny God, than admit He exists. For then they would have to admit their sin, and turn from their wicked ways, and that is just too much of a price for some to pay. They would rather choose darkness instead of light, evil over good, wrong over right, because it fits their own version of truth. If there is no higher authority than ourselves, then we accountable to no one and all things are acceptable.
However, like the Pharaoh of Egypt who continue to deny God and did what was right in his own eyes, all men who do the same will eventually come to the end of God's grace in their life and experience His judgment. Better to call upon Him now while He is still waiting for you to repent, than to continue to harden you heart against His Spirit and go your own way.
The Truth: “Happy is the man who is always reverent, but he who hardens his heart will fall into calamity.” (Proverbs 28:14)
