Mark 6:52
For they considered not the miracle of the loaves: for their heart was hardened.
Mark 3:5
And when he had looked round about on them with anger, being grieved for the hardness of their hearts, he saith unto the man, Stretch forth thine hand. And he stretched it out: and his hand was restored whole as the other.
Mark 8:17-21
And when Jesus knew it, he saith unto them, Why reason ye, because ye have no bread? perceive ye not yet, neither understand? have ye your heart yet hardened?
Isaiah 63:17
O LORD, why hast thou made us to err from thy ways, and hardened our heart from thy fear? Return for thy servants' sake, the tribes of thine inheritance.
Matthew 16:9-11
Do ye not yet understand, neither remember the five loaves of the five thousand, and how many baskets ye took up?
Mark 7:18
And he saith unto them, Are ye so without understanding also? Do ye not perceive, that whatsoever thing from without entereth into the man, it cannot defile him;
Mark 16:14
Afterward he appeared unto the eleven as they sat at meat, and upbraided them with their unbelief and hardness of heart, because they believed not them which had seen him after he was risen.
Luke 24:25
Then he said unto them, O fools, and slow of heart to believe all that the prophets have spoken:
Romans 11:7
What then? Israel hath not obtained that which he seeketh for; but the election hath obtained it, and the rest were blinded