Mark 4:12

that seeing they may see, and not perceive, and hearing they may hear, and not understand, lest at any time they should turn, and be forgiven.

Matthew 13:14-15

And in them is fulfilled the prophecy of Isaiah, which says; Hearing you shall hear and not understand, and seeing you shall see and not perceive;

Luke 8:10

And he said, It is given to you to know the mysteries of the kingdom of God, but to others in parables; that seeing they may not see, and hearing they may not understand.

John 12:37-41

But though he had performed so many miracles before them they did not believe in him;

Acts 3:19

Change your minds, therefore, and turn yourselves, that your sins may be blotted out, that times of refreshing may come from the presence of the Lord,

Acts 28:25-27

and disagreeing among themselves they were dismissed by Paul, saying one word; Well did the Holy Spirit speak by Isaiah the prophet to our fathers,

2 Timothy 2:25

in meekness correcting the adversaries, that God may give them a change of mind to a knowledge of the truth,

Hebrews 6:6

and having fallen away, it is impossible again to renew to a change of mind, they having crucified again and exposed to shame the Son of God.

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 says; Hearing you shall hear and not understand, and seeing you shall see and not perceive;
Luke 8:10
And he said, It is given to you to know the mysteries of the kingdom of God, but to others in parables; that seeing they may not see, and hearing they may not understand.
John 12:37
But though he had performed so many miracles before them they did not believe in him;
Acts 28:25
and disagreeing among themselves they were dismissed by Paul, saying one word; Well did the Holy Spirit speak by Isaiah the prophet to our fathers,

Be converted

Acts 3:19
Change your minds, therefore, and turn yourselves, that your sins may be blotted out, that times of refreshing may come from the presence of the Lord,
2 Timothy 2:25
in meekness correcting the adversaries, that God may give them a change of mind to a knowledge of the truth,
Hebrews 6:6
and having fallen away, it is impossible again to renew to a change of mind, they having crucified again and exposed to shame the Son of God.