Mark 6:52
"For they considered not the miracle of the loaves: for their heart was hardened."
Cross References (ranked by relevance)
Then he said unto them, O fools, and slow of heart to believe all that the prophets have spoken:
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.
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.
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.
What then? Israel hath not obtained that which he seeketh for; but the election hath obtained it, and the rest were blinded.
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;