Why did God harden Pharaoh’s heart? Did Pharaoh have free will?
Romans 9: 17-18 is used by Calvinist to prove that God will harden Pharaoh’s heart as if he has no free will.
However, the Bible shows that Pharaoh is the one who chose first to not let the people go, which is why God’s going to harden Pharaoh’s heart after that.
Notice that Exodus 3:19, Pharaoh is the first one that does not want to let the children of Israel go.
Notice again, Exodus 5:2, Pharaoh is the one that does not want to let the children of Israel go out of his free choice.
Then notice Exodus 7, the very first case of Pharaoh’s heart being hardened after that.
So it’s based on Pharaoh’s free choice first, which is why God hardened Pharaoh’s heart after that.
As a matter of fact, God hardened Pharaoh’s heart so that he could even repent.
It points out that God hardened the heart, so that Pharaoh can let the children of Israel go.
For a longer answer to this question, please read this article.