Hebrews 5:11
Of whom we have many things to say, and hard of interpretation, seeing ye are become dull of hearing.
2 Peter 3:16
as also in all his epistles, speaking in them of these things; wherein are some things hard to be understood, which the ignorant and unstedfast wrest, as they do also the other scriptures, unto their own destruction.
Matthew 13:15
For this people's heart is waxed gross, And their ears are dull of hearing, And their eyes they have closed; Lest haply they should perceive with their eyes, And hear with their ears, And understand with their heart, And should turn again, And I should heal them.
Isaiah 6:10
Make the heart of this people fat, and make their ears heavy, and shut their eyes; lest they sea with their eyes, and hear with their ears, and understand with their heart, and turn again, and be healed.
Mark 8:17-18
And Jesus perceiving it saith unto them, Why reason ye, because ye have no bread? do ye not yet perceive, neither understand? have ye your heart hardened?
Mark 8:21
And he said unto them, Do ye not yet understand?
Luke 24:25
And he said unto them, O foolish men, and slow of heart to believe in all that the prophets have spoken!
John 6:6
And this he said to prove him: for he himself knew what he would do.
John 16:12
I have yet many things to say unto you, but ye cannot bear them now.
Acts 28:27
For this people's heart is waxed gross, And their ears are dull of hearing, And their eyes they have closed; Lest, haply they should perceive with their eyes, And hear with their ears, And understand with their heart, And should turn again, And I should heal them.
1 Kings 10:1
And when the queen of Sheba heard of the fame of Solomon concerning the name of Jehovah, she came to prove him with hard questions.