Mark 4:12
so that for all their seeing they may not perceive, and for all their hearing they may not understand, lest they turn and be forgiven."
Luke 8:10
so he said, "It is granted you to understand the open secrets of the Reign of God, but the others get it in parables, so that for all their seeing they may not see, and for all their hearing they may not understand.
Matthew 13:14-15
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.
John 12:40
He has blinded their eyes and made their hearts insensible, to prevent them seeing with their eyes and understanding with their hearts and turning for me to cure them.
Acts 28:26-27
when he said, Go and tell this people, 'You will hear and hear but never understand, you will see and see but never perceive.'