Hebrews 5:11

Concerning whom we have much to say and difficult to be explained, since ye are become dull of hearing.

2 Peter 3:16

as also in all his epistles, speaking in them of these things: in which are some things hard to be understood, which the illiterate and unstable wrest, as they do also the other scriptures, to their own destruction.

Matthew 13:15

and their ears are dull of hearing, and they have closed their eyes; least they should see at all with their eyes, and hear with their ears, and understand with their heart, and be converted, and I should heal them.

Matthew 13:15

and their ears are dull of hearing, and they have closed their eyes; least they should see at all with their eyes, and hear with their ears, and understand with their heart, and be converted, and I should heal them.

Mark 8:17-18

And Jesus knowing it saith unto them, What are ye reasoning about? because ye have no bread? Do ye not yet discern nor understand? have ye your heart still hardened?

Mark 8:21

And He said unto them, How is it then that ye do not understand?

Luke 24:25

And He said unto them, O people void of understanding and slow of heart to believe all that the prophets have spoken.

John 6:6

(and this He said to try him, for He 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

and they hear heavily with their ears, and have closed their eyes; least they should see at all with their eyes, and hear with their ears, and understand with their heart, and be converted, and I should heal them.

Acts 28:27

and they hear heavily with their ears, and have closed their eyes; least they should see at all with their eyes, and hear with their ears, and understand with their heart, and be converted, and I should heal them.

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

John 6:6
(and this He said to try him, for He 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.
2 Peter 3:16
as also in all his epistles, speaking in them of these things: in which are some things hard to be understood, which the illiterate and unstable wrest, as they do also the other scriptures, to their own destruction.

Dull

Matthew 13:15
and their ears are dull of hearing, and they have closed their eyes; least they should see at all with their eyes, and hear with their ears, and understand with their heart, and be converted, and I should heal them.
Mark 8:17
And Jesus knowing it saith unto them, What are ye reasoning about? because ye have no bread? Do ye not yet discern nor understand? have ye your heart still hardened?
Luke 24:25
And He said unto them, O people void of understanding and slow of heart to believe all that the prophets have spoken.
Acts 28:27
and they hear heavily with their ears, and have closed their eyes; least they should see at all with their eyes, and hear with their ears, and understand with their heart, and be converted, and I should heal them.

General references

Mark 7:18
And He saith unto them, Are ye so void of understanding also? Do ye not know, that whatsoever from without entreth into a man cannot defile him?