The Torah teaches with precision and with mercy. At the beginning Pharaoh hardens his own heart. The text says his heart was heavy and unresponsive. Later the Torah states that God strengthened Pharaoh's heart. This shift is not accidental. It is judgment measured in stages.
In Hebrew three verbs appear. Kaved means heavy. A heart weighed down by arrogance. Kashe means hard. A heart resistant to truth. Chazak means strengthened. Not softened. Reinforced in the chosen direction. Strength without moral orientation becomes tyranny.
Exodus records that Pharaoh repeatedly refused to listen before God intervened. "And Pharaoh's heart was hardened, and he did not listen" Exodus 7:13. Only after sustained defiance does the verse change. "And the Lord strengthened the heart of Pharaoh" Exodus 9:12. Divine hardening is not the removal of free will. It is the sealing of a will already revealed.
This is a terrifying kindness. God allows a man to become what he insists on being. Pharaoh desired power without limit. Heaven granted him consistency. The plagues then became revelation rather than persuasion. Egypt learned. Israel learned. Pharaoh did not.
The Torah warns every ruler and every reader. If you ignore truth long enough you will still be free. Free only to continue downward with divine assistance.