Exodus 4:21 And the LORD said to Moses, When you go to return into Egypt, see that you do all those wonders before Pharaoh...
Exodus 7:13,14 And he hardened Pharaoh's heart, that he listened not to them; as the LORD had said...
Psalm 81:11,12 But my people would not listen to my voice; and Israel would none of me...
Revelation 16:10,11 And the fifth angel poured out his vial on the seat of the beast; and his kingdom was full of darkness...
Hardness of heart is a figurative expression, denoting that insensibility of mind upon which neither judgments nor mercies make any abiding impressions; but the conscience being stupefied, the obdurate rebel persists in determined disobedience.