John 12:40

"He hath blinded their eyes, and He hardened their heart, lest they should see with their eyes, and understand with their heart, and turn, and I should heal them."

Romans 9:18-20

So, then, He hath mercy on whom He willeth, and whom He willeth He hardeneth.

2 Thessalonians 2:11-12

And, for this cause, God sendeth them a working of delusion, that they may believe the lie;

Treasury of Scripture Knowledge

Summary

O LORD, why hast thou made us to err from thy ways, and hardened our heart from thy fear? Return for thy servants' sake, the tribes of thine inheritance.

And hardened

Bible References

Why

2 Thessalonians 2:11
And, for this cause, God sendeth them a working of delusion, that they may believe the lie;

And hardened

John 12:40
"He hath blinded their eyes, and He hardened their heart, lest they should see with their eyes, and understand with their heart, and turn, and I should heal them."
Romans 9:18
So, then, He hath mercy on whom He willeth, and whom He willeth He hardeneth.