How could God harden Pharaoh’s heart and then punish him for not letting the Jews go?

The Catholic Answers

The sense is that God permitted Pharaoh to harden his own heart. It is but a Jewish mode of speaking. Exod. VIII., 15, says, “And Pharaoh hardened his own heart.” God sent Moses to ask Pharaoh to let the Jews go, and that means that He meant Pharaoh to do so. God would not, therefore, have deliberately prevented Pharaoh from doing so. God permitted Pharaoh to harden his own heart, just as He permits men to sin even in our own days, if they are determined to do so.

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