Hebrews 3:8

⁶ But Christ is faithful as the Son over God’s house. And we are His house, if we hold firmly to our confidence and the hope of which we boast.

⁷ Therefore, as the Holy Spirit says: “Today, if you hear His voice,

do not harden your hearts, as you did in the rebellion, in the day of testing in the wilderness,

⁹ where your fathers tested and tried Me, and for forty years saw My works.

¹⁰ Therefore I was angry with that generation, and I said, ‘Their hearts are always going astray, and they have not known My ways.’

Do read the surrounding verses too, because the context often says more than a single verse.

Compare

BSB: do not harden your hearts, as you did in the rebellion, in the day of testing in the wilderness,
KJV: Harden not your hearts, as in the provocation, in the day of temptation in the wilderness:
WEB: don’t harden your hearts as in the rebellion, in the day of the trial in the wilderness,
ASV: Harden not your hearts, as in the provocation, Like as in the day of the trial in the wilderness,
DARBY: harden not your hearts, as in the provocation, in the day of temptation in the wilderness;
BLB: do not harden your⁺ hearts, as in the rebellion, in the day of testing in the wilderness,

ÅB: da forherd ikke deres hjerter som ved forbitrelsen, på fristelsesdagen i ørkenen,
OTB: så gjør ikke hjertene harde som under opprøret,
i prøvelsens tid i ørkenen,
B1930: da forherd ikke eders hjerter som ved forbitrelsen, på fristelsesdagen i ørkenen,

Proverbs 28:14
Blessed is the man who is always reverent, but he who hardens his heart falls into trouble.
Read in context
Exodus 17:7
He named the place Massah and Meribah because the Israelites quarreled, and because they tested the LORD, saying, “Is the LORD among us or not?”
Read in context
Matthew 13:15
For this people’s heart has grown callous; they hardly hear with their ears, and they have closed their eyes. Otherwise they might see with their eyes, hear with their ears, understand with their hearts, and turn, and I would heal them.’
Read in context
Zechariah 7:11–12
But they refused to pay attention and turned a stubborn shoulder; they stopped up their ears from hearing.
Read in context
Jeremiah 7:26
Yet they would not listen to Me or incline their ear, but they stiffened their necks and did more evil than their fathers.
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Daniel 5:20
But when his heart became arrogant and his spirit was hardened with pride, he was deposed from his royal throne, and his glory was taken from him.
Read in context
Psalms 78:56
But they tested and disobeyed God Most High, for they did not keep His decrees.
Read in context
Ezekiel 3:7–9
But the house of Israel will be unwilling to listen to you, since they are unwilling to listen to Me. For the whole house of Israel is hard-headed and hard-hearted.
Read in context