'Hardness' in the Bible

He told them, “Moses permitted you to divorce your wives because of the hardness of your hearts. But it was not like that from the beginning.

After looking around at them with anger and sorrow at the hardness of their hearts, He told the man, “Stretch out your hand.” So he stretched it out, and his hand was restored.

But Jesus told them, “He wrote this command for you because of the hardness of your hearts.

Later, He appeared to the Eleven themselves as they were reclining at the table. He rebuked their unbelief and hardness of heart, because they did not believe those who saw Him after He had been resurrected.

But because of your hardness and unrepentant heart you are storing up wrath for yourself in the day of wrath, when God’s righteous judgment is revealed.

They are darkened in their understanding, excluded from the life of God, because of the ignorance that is in them and because of the hardness of their hearts.