Mark 8:17
And when Jesus knew it, he said to them, Why reason you, because you have no bread? perceive you not yet, neither understand? have you your heart yet hardened?
Torrey's Topical Textbook—AKJV

Mark 16:14
Afterward he appeared to 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.
Torrey's Topical Textbook—AKJV