Exodus 4:21 The LORD said to Moses, "When you go back to Egypt see that you perform before Pharaoh all the wonders which I have put in your power; but I will harden his heart so that he will not let the people go.

Exodus 10:1 Then the LORD said to Moses, "Go to Pharaoh, for I have hardened his heart and the heart of his servants, that I may perform these signs of Mine among them,

Exodus 10:20 But the LORD hardened Pharaoh's heart, and he did not let the sons of Israel go.

Exodus 14:8 The LORD hardened the heart of Pharaoh, king of Egypt, and he chased after the sons of Israel as the sons of Israel were going out boldly.

Joshua 11:20 For it was of the LORD to harden their hearts, to meet Israel in battle in order that he might utterly destroy them, that they might receive no mercy, but that he might destroy them, just as the LORD had commanded Moses.

John 12:40 "HE HAS BLINDED THEIR EYES AND HE HARDENED THEIR HEART, SO THAT THEY WOULD NOT SEE WITH THEIR EYES AND PERCEIVE WITH THEIR HEART, AND BE CONVERTED AND I HEAL THEM." (NASB ©1995)