Deuteronomy 10:16

So circumcise your heart, and stiffen your neck no longer.

Jeremiah 4:4

Circumcise yourselves to the Lord
And remove the foreskins of your heart,
Men of Judah and inhabitants of Jerusalem,
Or else My wrath will go forth like fire
And burn with none to quench it,
Because of the evil of your deeds.”

Deuteronomy 9:6

“Know, then, it is not because of your righteousness that the Lord your God is giving you this good land to possess, for you are a stubborn people.

Deuteronomy 30:6

“Moreover the Lord your God will circumcise your heart and the heart of your descendants, to love the Lord your God with all your heart and with all your soul, so that you may live.

Leviticus 26:41

I also was acting with hostility against them, to bring them into the land of their enemies—or if their uncircumcised heart becomes humbled so that they then make amends for their iniquity,

Romans 2:28-29

For he is not a Jew who is one outwardly, nor is circumcision that which is outward in the flesh.

Colossians 2:11

and in Him you were also circumcised with a circumcision made without hands, in the removal of the body of the flesh by the circumcision of Christ;

Deuteronomy 9:13

The Lord spoke further to me, saying, ‘I have seen this people, and indeed, it is a stubborn people.

Deuteronomy 31:27

For I know your rebellion and your stubbornness; behold, while I am still alive with you today, you have been rebellious against the Lord; how much more, then, after my death?

Jeremiah 4:14

Wash your heart from evil, O Jerusalem,
That you may be saved.
How long will your wicked thoughts
Lodge within you?

James 4:6-7

But He gives a greater grace. Therefore it says, “God is opposed to the proud, but gives grace to the humble.”

Treasury of Scripture Knowledge

Summary

Circumcise therefore the foreskin of your heart, and be no more stiffnecked.

Bible References

Stiff-necked

Deuteronomy 9:6
“Know, then, it is not because of your righteousness that the Lord your God is giving you this good land to possess, for you are a stubborn people.
Deuteronomy 31:27
For I know your rebellion and your stubbornness; behold, while I am still alive with you today, you have been rebellious against the Lord; how much more, then, after my death?
James 4:6
But He gives a greater grace. Therefore it says, “God is opposed to the proud, but gives grace to the humble.”