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.

Treasury of Scripture Knowledge

Summary

Of whom we have many things to say, and hard to be uttered, seeing ye are dull of hearing.

General references

Bible References

We

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.
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.
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.

Dull

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.
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.
Mark 8:17
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?
Luke 24:25
And he said unto them, O foolish men, and slow of heart to believe in all that the prophets have spoken!
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.

General references

Leviticus 11:22
Even these of them ye may eat: the locust after its kind, and the bald locust after its kind, and the cricket after its kind, and the grasshopper after its kind.
Mark 7:18
And he saith unto them, Are ye so without understanding also? Perceive ye not, that whatsoever from without goeth into the man, it cannot defile him;

American Standard Version Public Domain