Hebrews 3:8

harden not your hearts, as in the provocation, in the day of temptation in the wilderness,

Matthew 13:15

for the heart of this people was made gross, and with their ears they heard heavily, and their eyes they closed; lest they should see with their eyes, and hear with their ears, and understand with their heart, and turn, and I should heal them.'

Acts 19:9

But, when some were hardening themselves and were disbelieving, speaking evil of the Way before the multitude, he, withdrawing from them, separated the disciples; reasoning daily in the school of Tyrannus.

Romans 2:5-6

but, after your hardness and impenitent heart, you are treasuring up for yourself wrath in the day of wrath and of the revelation of the righteous judgment of God,

1 Corinthians 10:9

Nor let us tempt the Lord, as some of them tempted Him, and perished by the serpents.

Hebrews 3:12-13

Take heed, brethren, lest at any time there shall be in anyone of you an evil heart of unbelief, in falling away from the living God;

Treasury of Scripture Knowledge

Summary

Harden not your hearts, as in the provocation, in the day of temptation in the wilderness:

General references

Bible References

Harden

Hebrews 3:12
Take heed, brethren, lest at any time there shall be in anyone of you an evil heart of unbelief, in falling away from the living God;
Matthew 13:15
for the heart of this people was made gross, and with their ears they heard heavily, and their eyes they closed; lest they should see with their eyes, and hear with their ears, and understand with their heart, and turn, and I should heal them.'
Acts 19:9
But, when some were hardening themselves and were disbelieving, speaking evil of the Way before the multitude, he, withdrawing from them, separated the disciples; reasoning daily in the school of Tyrannus.
Romans 2:5
but, after your hardness and impenitent heart, you are treasuring up for yourself wrath in the day of wrath and of the revelation of the righteous judgment of God,

Of

1 Corinthians 10:9
Nor let us tempt the Lord, as some of them tempted Him, and perished by the serpents.

General references

Luke 8:6
And another fell upon the rock; and, springing up, it was withered because of not having moisture.