Mark 4:12

in order that seeing they may see, and not know; and hearing they may hear, and not understand; lest they may turn, and their sins may he forgiven unto them.

Matthew 13:14-15

And the prophecy of Isaiah is fulfilled unto them, saying, By hearing ye shall hear, and may not understand; and seeing you shall see, and may not perceive.

Luke 8:10

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

John 12:37-41

And He having done so many miracles in their presence, they were not believing on Him,

Acts 3:19

Repent, therefore, and turn, that your sins may be blotted out, in order that seasons of soul-renewing may come from the presence of the Lord,

Acts 28:25-27

and they being disharmonious to one another, dispersed, Paul saying one word, that truly the Holy Ghost spoke through the prophet Isaiah to your fathers, saying,

Romans 11:8-10

as has been written, God has given them the spirit of slumber, eyes that they should not see, and ears that they should not hear, unto this day.

2 Timothy 2:25

in meekness correcting the adversaries; if peradventure God may grant unto them repentance into the perfect knowledge of the truth,

Hebrews 6:6

indeed having fallen away, to renew them again unto repentance; having crucified to themselves again the Son of God, and put him to an 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.

Bible References

That seeing

Matthew 13:14
And the prophecy of Isaiah is fulfilled unto them, saying, By hearing ye shall hear, and may not understand; and seeing you shall see, and may not perceive.
Luke 8:10
And He said; To you it has been given to know the mysteries of the kingdom of God: but to the rest in parables; in order that seeing they may not see, and hearing they may not understand.
John 12:37
And He having done so many miracles in their presence, they were not believing on Him,
Acts 28:25
and they being disharmonious to one another, dispersed, Paul saying one word, that truly the Holy Ghost spoke through the prophet Isaiah to your fathers, saying,
Romans 11:8
as has been written, God has given them the spirit of slumber, eyes that they should not see, and ears that they should not hear, unto this day.

Be converted

Acts 3:19
Repent, therefore, and turn, that your sins may be blotted out, in order that seasons of soul-renewing may come from the presence of the Lord,
2 Timothy 2:25
in meekness correcting the adversaries; if peradventure God may grant unto them repentance into the perfect knowledge of the truth,
Hebrews 6:6
indeed having fallen away, to renew them again unto repentance; having crucified to themselves again the Son of God, and put him to an open shame.