Exodus 8:16
Then the LORD said to Moses, "Tell Aaron, 'Stretch out your staff and strike the dust of the earth, that it may turn into swarms of gnats throughout the land of Egypt.'"

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

Exodus 7:13, 14
Still, Pharaoh's heart was hardened, and he did not listen to them, just as the LORD had said. . . .

Isaiah 63:17
Why, O LORD, do You make us stray from Your ways and harden our hearts from fearing You? Return, for the sake of Your servants, the tribes of Your heritage.

Acts 28:26, 27
Go to this people and say, "You will be ever hearing but never understanding; you will be ever seeing but never perceiving." . . .

Romans 2:5
But because of your hard and unrepentant heart, you are storing up wrath against yourself for the day of wrath, when God's righteous judgment will be revealed.

James 1:13, 14
When tempted, no one should say, "God is tempting me." For God cannot be tempted by evil, nor does He tempt anyone. . . .