Hebrews 5:11
About whom, much subject matter from us is also difficult to explain, since ye have become sluggish in hearing.
2 Peter 3:16
as also in all his letters, speaking in them about these things, in which are some things hard to understand, which the ignorant and unstable twist, as also the other scriptures, to their own destruction.
Matthew 13:15
For this people's heart became fat, and their ears hear heavily, and their eyes are shut, lest they should see with their eyes, and hear with their ears, and understand with their heart, and should turn, and I will heal them.
Isaiah 6:10
Make the heart of this people fat, and make their ears heavy, and shut their eyes, lest they see with their eyes, and hear with their ears, and understand with their heart, and turn, and be healed.
Mark 8:17-18
And knowing it Jesus says to them, Why do ye deliberate because ye have no loaves? Do ye not yet perceive nor understand? Have ye your heart still hardened?
Mark 8:21
And he said to them, How do ye not understand?
Luke 24:25
And he said to them, O foolish men, and slow of heart to believe in all that the prophets spoke.
John 6:6
But he said this testing him, for he himself knew what he was going to do.
John 16:12
I have yet many things to say to you, but ye cannot bear them now.
Acts 28:27
For this people's heart was made fat, and they hear heavily with the ears. And they shut their eyes, lest they may perceive with the eyes, and hear with the ears, and understand with the heart, and should turn, and I would heal the
1 Kings 10:1
And when the queen of Sheba heard of the fame of Solomon concerning the name of LORD, she came to prove him with hard questions.