'Stiff necked' in the Bible

Understand therefore that it is not for thy righteousness' sake, that the LORD thy God doth give thee this good land to possess it, for thou art a stiff-necked people.

Furthermore the LORD spake unto me, saying, 'I see this people how that it is a stiff-necked people;

Circumcise, therefore, the foreskin of your hearts, and be no longer stiff-necked.