Mark 8:17-18
He noted this and said to them, "Why do you argue you have no bread? Do you not see, do you not understand, even yet? Are you still dull of heart?
Luke 24:25
He said to them, "O foolish men, with hearts so slow to believe, after all the prophets have declared!
John 3:19
And this is the sentence of condemnation, that the Light has entered the world and yet men have preferred darkness to light. It is because their actions have been evil;
Matthew 13:14
In their case the prophecy of Isaiah is being fulfilled: You will hear and hear but never understand, you will see and see but never perceive.