Mark 4:12

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

Matthew 13:14-15

And in them is fulfilled the prophecy of Isaiah, which saith, With the hearing ye shall hear, and not understand; and seeing ye shall see, and in no wise perceive:

Luke 8:10

And he said, To you it is given to know the mysteries of the kingdom of God; but to the rest in parables: that seeing they may not perceive, and hearing may not comprehend.

John 12:37-41

Now, though he had done so many miracles before them, they believed not on him:

Acts 3:19

Repent ye therefore, and be converted, that your sins may be blotted out, when refreshing seasons shall come from the presence of the Lord;

Acts 28:25-27

So being divided in sentiment among themselves, they broke up, Paul adding one word, That well had the Holy Ghost spoken by Isaiah the prophet unto our fathers,

Romans 11:8-10

as it is written, "God hath given them the spirit of slumber, eyes that they should not see, and ears that they should not hear; unto this present day."

2 Timothy 2:25

with meekness correcting those who are opposers, if at last God may give unto them repentance so as to submit to the conviction of the truth;

Hebrews 6:6

and yet have fallen away: for they crucify again to themselves the Son of God, and expose him to public infamy.

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.

Bible References

That seeing

Matthew 13:14
And in them is fulfilled the prophecy of Isaiah, which saith, With the hearing ye shall hear, and not understand; and seeing ye shall see, and in no wise perceive:
Luke 8:10
And he said, To you it is given to know the mysteries of the kingdom of God; but to the rest in parables: that seeing they may not perceive, and hearing may not comprehend.
John 12:37
Now, though he had done so many miracles before them, they believed not on him:
Acts 28:25
So being divided in sentiment among themselves, they broke up, Paul adding one word, That well had the Holy Ghost spoken by Isaiah the prophet unto our fathers,
Romans 11:8
as it is written, "God hath given them the spirit of slumber, eyes that they should not see, and ears that they should not hear; unto this present day."

Be converted

Acts 3:19
Repent ye therefore, and be converted, that your sins may be blotted out, when refreshing seasons shall come from the presence of the Lord;
2 Timothy 2:25
with meekness correcting those who are opposers, if at last God may give unto them repentance so as to submit to the conviction of the truth;
Hebrews 6:6
and yet have fallen away: for they crucify again to themselves the Son of God, and expose him to public infamy.