Mark 4:12

They may surely look and yet not see, and surely hear and yet not understand, lest once they should return and it be forgiven them.

Isaiah 6:9-10

Then said be - Go and say unto this people, - Hear on but do not discern, See on but do not perceive:

Jeremiah 5:21

Hear this, I pray you ye people - foolish and without heart, - Eyes, have they, and see not, Ears, have they, and hear not!

Deuteronomy 29:4

yet hath Yahweh not given onto you a heart to know, or eyes to see or ears to hear, - until this day.

Jeremiah 31:18-20

I have, heard, Ephraim bemoaning himself, Thou hast chastised me and I have been chastised, Like a bullock, not broken in, Suffer me to return that I may return, For thou, art Yahweh my God.

Matthew 13:14-15

And, again is being fulfilled in them, the prophecy of Isaiah, which saith, - They shall, surely hear, and yet will not understand, and, surely see, and yet not perceive;

Luke 8:10

And, he, said - Unto you, hath it been given, to get to know the sacred secrets of the kingdom of God; but, unto the rest, in parables, - in order that, seeing, they may not see, and, hearing, they may not understand.

Isaiah 44:18

They have not taken note, neither can they perceive, - He hath besmeared - past seeing - their eyes, Past understanding, their hearts;

Ezekiel 12:2

Son of man. In the midst of a perverse house, dost thou dwell, - Who have eyes to see - and have not seen. Ears have they to hear - and have no heard, For a perverse house, they are.

Ezekiel 18:27-32

But when a lawless man turneth away from his lawlessness which he hath done, And hath done justice and righteousness He, shall save his own soul, alive:

John 12:37-41

And, although such signs, as these, he had done before them, they were not believing on him: -

Acts 3:19

Repent ye, therefore, and turn, - unto the blotting out of your sins; to the end that in that case, there may come seasons of refreshing from the face of the Lord,

Acts 28:25-27

and, not being, agreed, among themselves, they began to leave, - Paul having said one thing - Well, did, the Holy Spirit, speak through Isaiah the prophet, unto your fathers,

Romans 11:8-10

Even as it is written - God hath given unto them a spirit of stupor, - eyes not to see, and ears not to hear, - until this very day;

2 Timothy 2:25

In meekness, bringing under discipline them that oppose themselves, lest at any time God should give them repentance unto a personal knowledge of truth,

Hebrews 6:6

And who have fallen away, again, to be remoulding them into repentance; seeing they are again crucifying unto themselves the Son of God, and holding him up as an example.

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 hath Yahweh not given onto you a heart to know, or eyes to see or ears to hear, - until this day.
Isaiah 6:9
Then said be - Go and say unto this people, - Hear on but do not discern, See on but do not perceive:
Isaiah 44:18
They have not taken note, neither can they perceive, - He hath besmeared - past seeing - their eyes, Past understanding, their hearts;
Jeremiah 5:21
Hear this, I pray you ye people - foolish and without heart, - Eyes, have they, and see not, Ears, have they, and hear not!
Matthew 13:14
And, again is being fulfilled in them, the prophecy of Isaiah, which saith, - They shall, surely hear, and yet will not understand, and, surely see, and yet not perceive;
Luke 8:10
And, he, said - Unto you, hath it been given, to get to know the sacred secrets of the kingdom of God; but, unto the rest, in parables, - in order that, seeing, they may not see, and, hearing, they may not understand.
John 12:37
And, although such signs, as these, he had done before them, they were not believing on him: -
Acts 28:25
and, not being, agreed, among themselves, they began to leave, - Paul having said one thing - Well, did, the Holy Spirit, speak through Isaiah the prophet, unto your fathers,
Romans 11:8
Even as it is written - God hath given unto them a spirit of stupor, - eyes not to see, and ears not to hear, - until this very day;

Be converted

Jeremiah 31:18
I have, heard, Ephraim bemoaning himself, Thou hast chastised me and I have been chastised, Like a bullock, not broken in, Suffer me to return that I may return, For thou, art Yahweh my God.
Ezekiel 18:27
But when a lawless man turneth away from his lawlessness which he hath done, And hath done justice and righteousness He, shall save his own soul, alive:
Acts 3:19
Repent ye, therefore, and turn, - unto the blotting out of your sins; to the end that in that case, there may come seasons of refreshing from the face of the Lord,
2 Timothy 2:25
In meekness, bringing under discipline them that oppose themselves, lest at any time God should give them repentance unto a personal knowledge of truth,
Hebrews 6:6
And who have fallen away, again, to be remoulding them into repentance; seeing they are again crucifying unto themselves the Son of God, and holding him up as an example.

General references

Proverbs 28:5
Wicked men, consider not justice, but, they who seek Yahweh, consider everything.