Mark 4:12

so that while seeing, they may see and not perceive, and while hearing, they may hear and not understand, otherwise they might return and be forgiven.”

Isaiah 6:9-10

He said, “Go, and tell this people:
‘Keep on listening, but do not perceive;
Keep on looking, but do not understand.’

Jeremiah 5:21

‘Now hear this, O foolish and senseless people,
Who have eyes but do not see;
Who have ears but do not hear.

Deuteronomy 29:4

Yet to this day the Lord has not given you a heart to know, nor eyes to see, nor ears to hear.

Jeremiah 31:18-20

“I have surely heard Ephraim grieving,
‘You have chastised me, and I was chastised,
Like an untrained calf;
Bring me back that I may be restored,
For You are the Lord my God.

Matthew 13:14-15

In their case the prophecy of Isaiah is being fulfilled, which says,
You will keep on hearing, but will not understand;
You will keep on seeing, but will not perceive;

Luke 8:10

And He said, To you it has been granted to know the mysteries of the kingdom of God, but to the rest it is in parables, so that seeing they may not see, and hearing they may not understand.

Isaiah 44:18

They do not know, nor do they understand, for He has smeared over their eyes so that they cannot see and their hearts so that they cannot comprehend.

Ezekiel 12:2

“Son of man, you live in the midst of the rebellious house, who have eyes to see but do not see, ears to hear but do not hear; for they are a rebellious house.

Ezekiel 18:27-32

Again, when a wicked man turns away from his wickedness which he has committed and practices justice and righteousness, he will save his life.

John 12:37-41

But though He had performed so many signs before them, yet they were not believing in Him.

Acts 3:19

Therefore repent and return, so that your sins may be wiped away, in order that times of refreshing may come from the presence of the Lord;

Acts 28:25-27

And when they did not agree with one another, they began leaving after Paul had spoken one parting word, “The Holy Spirit rightly spoke through Isaiah the prophet to your fathers,

Romans 11:8-10

just as it is written,
God gave them a spirit of stupor,
Eyes to see not and ears to hear not,
Down to this very day.”

2 Timothy 2:25

with gentleness correcting those who are in opposition, if perhaps God may grant them repentance leading to the knowledge of the truth,

Hebrews 6:6

and then have fallen away, it is impossible to renew them again to repentance, since they again crucify to themselves the Son of God and put Him to open shame.

Treasury of Scripture Knowledge

Summary

That seeing they may see, and not perceive; and hearing they may hear, and not understand; lest at any time they should be converted, and their sins should be forgiven them.

General references

Bible References

That seeing

Deuteronomy 29:4
Yet to this day the Lord has not given you a heart to know, nor eyes to see, nor ears to hear.
Isaiah 6:9
He said, “Go, and tell this people:
‘Keep on listening, but do not perceive;
Keep on looking, but do not understand.’
Isaiah 44:18
They do not know, nor do they understand, for He has smeared over their eyes so that they cannot see and their hearts so that they cannot comprehend.
Jeremiah 5:21
‘Now hear this, O foolish and senseless people,
Who have eyes but do not see;
Who have ears but do not hear.
Matthew 13:14
In their case the prophecy of Isaiah is being fulfilled, which says,
You will keep on hearing, but will not understand;
You will keep on seeing, but will not perceive;
Luke 8:10
And He said, To you it has been granted to know the mysteries of the kingdom of God, but to the rest it is in parables, so that seeing they may not see, and hearing they may not understand.
John 12:37
But though He had performed so many signs before them, yet they were not believing in Him.
Acts 28:25
And when they did not agree with one another, they began leaving after Paul had spoken one parting word, “The Holy Spirit rightly spoke through Isaiah the prophet to your fathers,
Romans 11:8
just as it is written,
God gave them a spirit of stupor,
Eyes to see not and ears to hear not,
Down to this very day.”

Be converted

Jeremiah 31:18
“I have surely heard Ephraim grieving,
‘You have chastised me, and I was chastised,
Like an untrained calf;
Bring me back that I may be restored,
For You are the Lord my God.
Ezekiel 18:27
Again, when a wicked man turns away from his wickedness which he has committed and practices justice and righteousness, he will save his life.
Acts 3:19
Therefore repent and return, so that your sins may be wiped away, in order that times of refreshing may come from the presence of the Lord;
2 Timothy 2:25
with gentleness correcting those who are in opposition, if perhaps God may grant them repentance leading to the knowledge of the truth,
Hebrews 6:6
and then have fallen away, it is impossible to renew them again to repentance, since they again crucify to themselves the Son of God and put Him to open shame.

General references

Proverbs 28:5
Evil men do not understand justice,
But those who seek the Lord understand all things.