John 8:27

They understood not that he spoke to them concerning the Father.

Isaiah 6:9

And he said, Go, and tell this people, Hear ye indeed, but understand not; and see ye indeed, but perceive not.

Isaiah 42:18-20

Hear, ye deaf; and look, ye blind, that ye may see.

Isaiah 59:10

We grope for the wall like the blind, and we grope as if we had no eyes: we stumble at noon day as in the night; we are in desolate places as dead men.

John 8:43

Why do ye not understand my speech? even because ye cannot hear my word.

John 8:47

He that is of God, heareth God's words: ye therefore hear them not, because ye are not of God.

Romans 11:7-10

What then? Israel hath not obtained that which he seeketh for; but the election hath obtained it, and the rest were blinded.

2 Corinthians 4:3-4

But if our gospel is hid, it is hid to them that are lost:

Treasury of Scripture Knowledge

Summary

They understood not that he spake to them of the Father.

Bible References

General references

John 8:43
Why do ye not understand my speech? even because ye cannot hear my word.
Isaiah 6:9
And he said, Go, and tell this people, Hear ye indeed, but understand not; and see ye indeed, but perceive not.
Isaiah 42:18
Hear, ye deaf; and look, ye blind, that ye may see.
Isaiah 59:10
We grope for the wall like the blind, and we grope as if we had no eyes: we stumble at noon day as in the night; we are in desolate places as dead men.
Romans 11:7
What then? Israel hath not obtained that which he seeketh for; but the election hath obtained it, and the rest were blinded.
2 Corinthians 4:3
But if our gospel is hid, it is hid to them that are lost: