The account appears to indicate Pharaoh’s heart was already hard and cruel. God simply expedited Pharaoh’s character and heart condition.
Maybe these linked articles will give you some food for thought on this topic, if you’re interested...
“According to Adam Clarke's commentary, the Hebrew word translated
harden "literally signifies to strengthen, confirm, make bold or courageous." An illustration commonly heard is that of a sponge squeezed (made hard) in the hand. Anything that comes forth from the squeezed sponge was already there. When God "hardened" Pharaoh's heart, He simply forced out what was already there, strengthening Pharaoh's own convictions.”
Question: Did God take away Pharaoh's free will when He "hardened Pharaoh's heart" (Exodus 10:1-2)? What verses point to free will in the Bible?
In Defense of the Faith