John 12:39

For this cause they could not believe, for Isaiah said again,

John 5:44

How can you believe, who receive glory from one another, and you do not seek the glory that comes from the only God?

Isaiah 6:9-10

He said, "Go, and tell this people, 'You hear indeed, but do not understand; and you see indeed, but do not perceive.'

Isaiah 44:18-20

They do not know, neither do they consider: for he has shut their eyes, that they can't see; and their hearts, that they can't understand.

John 6:44

No one can come to me unless the Father who sent me draws him, and I will raise him up in the last day.

John 10:38

But if I do them, though you do not believe me, believe the works; that you may know and understand that the Father is in me, and I in the Father."

2 Peter 2:14

having eyes full of adultery, and who cannot cease from sin; enticing unsettled souls; having a heart trained in greed; children of cursing;

Treasury of Scripture Knowledge

Summary

Therefore they could not believe, because that Esaias said again,

Bible References

They

John 5:44
How can you believe, who receive glory from one another, and you do not seek the glory that comes from the only God?
John 6:44
No one can come to me unless the Father who sent me draws him, and I will raise him up in the last day.
John 10:38
But if I do them, though you do not believe me, believe the works; that you may know and understand that the Father is in me, and I in the Father."
Isaiah 44:18
They do not know, neither do they consider: for he has shut their eyes, that they can't see; and their hearts, that they can't understand.
2 Peter 2:14
having eyes full of adultery, and who cannot cease from sin; enticing unsettled souls; having a heart trained in greed; children of cursing;

General references

Exodus 10:20
But the LORD hardened Pharaoh's heart, and he did not let the children of Israel go.
Deuteronomy 29:4
but the LORD has not given you a heart to know, and eyes to see, and ears to hear, to this day.
John 1:5
And the light shines in the darkness, and the darkness hasn't overcome it.
John 9:18
The Jewish leaders therefore did not believe concerning him, that he had been blind, and had received his sight, until they called the parents of him who had received his sight,
John 10:37
If I do not do the works of my Father, do not believe me.