Mark 6:52
For they did not understand the miracle of the loaves, for their hearts were hardened.
Mark 3:5
And looking around on them with anger, being grieved because of the hardness of their hearts, He said to the man, Stretch out your hand! And he stretched it out. And his hand was restored whole, like the other.
Mark 8:17-21
And knowing it, Jesus said to them, Why do you reason that it is because you have no loaves? Do you not yet perceive nor understand? Have you still hardened your heart?
Isaiah 63:17
O Jehovah, why have You made us wander from Your ways. You harden our heart from Your fear? For Your servants' sake, return the tribes of Your inheritance.
Matthew 16:9-11
Do you not yet understand, nor remember the five loaves of the five thousand, and how many hand baskets you took up;
Mark 7:18
And He said to them, Are you also without understanding? Do you not perceive that whatever enters into the man from outside cannot defile him,
Mark 16:14
Afterward He appeared to the Eleven as they reclined. And He reproached their unbelief and hardness of heart, because they did not believe those who had seen Him after He had risen.
Luke 24:25
And He said to them, O fools and slow of heart to believe all things that the prophets spoke!
Romans 11:7
What then? Israel has not obtained that which it seeks, but the election obtained it, and the rest were hardened