King James Version (KJV)

Hebrews 3:13

“But exhort one another daily, while it is called To day; lest any of you be hardened through the deceitfulness of sin.”

Verse in context — Hebrews 3

So I sware in my wrath, They shall not enter into my rest.)

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 To day; lest any of you be hardened through the deceitfulness of sin.

For we are made partakers of Christ, if we hold the beginning of our confidence stedfast unto the end;

While it is said, To day if ye will hear his voice, harden not your hearts, as in the provocation.

Jesus as the ultimate High Priest and fulfillment of the Old Covenant.