Hebrews 3:8

Heb. 3:8. Harden not your hearts, as in the provocation, in the day of temptation in the wilderness:

Again, as often, Hebrews appears in Religious Affections :

10. 'Tis an evidence that true religion, or holiness of heart, lies very much in the affection of the heart, that the Scriptures place the sin of the heart very much in hardness of heart. Thus the Scriptures do everywhere. It was hardness of heart, which excited grief and displeasure in Christ towards the Jews…. God's leaving men to the power of the sin and corruption of the heart, is often expressed by God's hardening their hearts; "Therefore hath he mercy on whom he will have mercy, and whom he will he hardeneth" (Romans 9:18). "He hath blinded their minds, and hardened their hearts" (John 12:40). And the Apostle seems to speak of an evil heart, that departs from the living God, and a hard heart, as the same thing, "Harden not your heart, as in the provocation," etc. (Hebrews 3:8). "Take heed, brethren, lest there be in any of you an evil heart of unbelief, in departing from the living God; but exhort one another daily, while it is called Today; lest any of you be hardened through the deceitfulness of sin" (Hebrews 3:12; Hebrews 3:13).

Heb. 3:9-12