'Stiffen' in the Bible

Circumcise then the foreskin of your heart, and stiffen your neck no more.

Now do not stiffen your neck like your fathers, but yield to the Lord and enter His sanctuary which He has consecrated forever, and serve the Lord your God, that His burning anger may turn away from you.

And they have not hearkened nor inclined their ear, And they stiffen their neck not to hear, And not to receive instruction.