Romans 2:5
But according to thy hardness and thy impenitent heart, thou art treasuring up to thyself wrath against the day of wrath and of the revelation of the righteous judgment of God;
Hebrews 3:8-9
harden not your hearts, as in the provocation, in the day of temptation in the wilderness,
Hebrews 3:13
but exhort one another each day, while it is called to-day; in order that no one of you may be hardened with the deceitfulness of sin:
Hebrews 3:15-19
In that it is said, This day if you hear his voice, harden not your hearts, as in the provocation:
Hebrews 12:25
See that you do not reject the one speaking: for if they escape not having rejected the one delivering them the divine oracles on earth, how much more shall we not escape, who turn away from the one speaking from the heavens:
Jude 1:5
But I wish you to remember, once having known all these things, that the Lord, having saved the people out of the land of Egypt, destroyed them that believed riot, the second time:
Acts 19:9
But when some were becoming hardened and disbelieving, speaking evil of the way in the presence of the multitude, departing from them he separated his disciples, daily expounding in the school of Tyrannus.