Romans 2:5
But according to thy hardness and impenitent heart, thou art treasuring up for thyself wrath against the day of wrath and of the manifestation of the righteous judgment of God,
Hebrews 3:8-9
harden not your hearts, as in the provocation, in the day of the temptation in the wilderness,
Hebrews 3:13
But exhort one another daily, as long as it is called Today, that none of you may be hardened through the deceitfulness of sin.
Hebrews 3:15-19
When it is said, "Today, if ye hear his voice, harden not your hearts, as in the provocation,"
Hebrews 12:25
See that ye refuse not him who speaketh. For if they did not escape, who refused him who spoke his will on earth, much more shall not we, if we turn away from him who speaketh from heaven;
Jude 1:5
But I wish to remind you as once knowing it all, that the Lord, having saved the people out of the land of Egypt, afterward destroyed those who believed not;
Acts 19:9
But when some were hardened, and believed not, but spoke evil of the way [of the Lord] before the multitude, he departed from them, and separated the disciples, discoursing daily in the school of Tyrannus.