Joshua 11:20

For it was Yahweh that {hardened their hearts}, to meet Israel in war in order to utterly destroy them without mercy, that they would destroy them just as Yahweh commanded Moses.

Deuteronomy 20:16-17

But from the cities of these peoples that Yahweh your God [is] giving to you as an inheritance, you shall not let anything live that breathes.

Exodus 4:21

And Yahweh said to Moses, "When you go to return to Egypt, see all of the wonders that I have put in your hand, and do them before Pharaoh, and I myself will harden his heart, and he will not release the people.

Deuteronomy 7:16

And you shall devour all of the peoples [that] Yahweh your God [is] giving to you; {you shall not pity them}, and you shall not serve their gods, [which] will be a snare for you.

Romans 9:18

Consequently therefore, he has mercy on whomever he wishes, and he hardens whomever he wishes.

Exodus 9:16

But for the sake of this I have caused you to stand--for the sake of showing you my strength and in order to proclaim my name in all the earth.

Exodus 14:17

And as for me, look, I [am] about to harden the heart of [the] Egyptians [so that] they come after them, and I will display my glory through Pharaoh and through all of his army, through his chariots and through his charioteers.

Deuteronomy 2:30

But Sihon king of Heshbon was not willing to let us cross through his [territory] because Yahweh your God hardened his spirit and {made him obstinate} {in order to give him} into your hand, {just as he has now done}.

Joshua 11:12-15

And Joshua captured all the cities of these kings, and all their kings, and he utterly destroyed them with {the edge of the sword}, as Moses the servant of Yahweh commanded.

Judges 14:4

His father and mother did not know that this [was] from Yahweh; he was seeking for an occasion against [the] Philistines. Now at that time [the] Philistines [were] ruling in Israel.

1 Samuel 2:25

If a man sins against a man, then God can intercede for him. But if a man sins against Yahweh, who can intercede for him?" But they did not {obey} their father, because Yahweh wanted to kill them.

1 Kings 12:15

So the king did not listen to the people, for it was a turning of events from Yahweh in order to fulfill his word which Yahweh had spoken through the hand of Ahijah the Shilonite to Jeroboam the son of Nebat.

1 Kings 22:20-23

And Yahweh said, 'Who will entice Ahab so that he will go up and fall at Ramoth-Gilead?' Then {this one was saying one thing and the other one was saying another}.

2 Chronicles 25:16

And it happened [that] while he was speaking to him, he said to him, "Have we appointed you as a counselor to the king? Stop--{why should you be killed}?" So the prophet stopped and said, "I know that God has determined to destroy you, because you have done this and have not listened to my advice."

Isaiah 6:9-10

And he said, "Go and say to this people, 'Keep on listening and do not comprehend! And keep on looking and do not understand!'

Romans 9:22-23

And [what] if God, wanting to demonstrate his wrath and to make known his power, endured with much patience vessels of wrath prepared for destruction?

Treasury of Scripture Knowledge

Summary

For it was of the LORD to harden their hearts, that they should come against Israel in battle, that he might destroy them utterly, and that they might have no favour, but that he might destroy them, as the LORD commanded Moses.

Bible References

It was

Exodus 4:21
And Yahweh said to Moses, "When you go to return to Egypt, see all of the wonders that I have put in your hand, and do them before Pharaoh, and I myself will harden his heart, and he will not release the people.
Exodus 9:16
But for the sake of this I have caused you to stand--for the sake of showing you my strength and in order to proclaim my name in all the earth.
Deuteronomy 2:30
But Sihon king of Heshbon was not willing to let us cross through his [territory] because Yahweh your God hardened his spirit and {made him obstinate} {in order to give him} into your hand, {just as he has now done}.
Judges 14:4
His father and mother did not know that this [was] from Yahweh; he was seeking for an occasion against [the] Philistines. Now at that time [the] Philistines [were] ruling in Israel.
1 Samuel 2:25
If a man sins against a man, then God can intercede for him. But if a man sins against Yahweh, who can intercede for him?" But they did not {obey} their father, because Yahweh wanted to kill them.
1 Kings 12:15
So the king did not listen to the people, for it was a turning of events from Yahweh in order to fulfill his word which Yahweh had spoken through the hand of Ahijah the Shilonite to Jeroboam the son of Nebat.
1 Kings 22:20
And Yahweh said, 'Who will entice Ahab so that he will go up and fall at Ramoth-Gilead?' Then {this one was saying one thing and the other one was saying another}.
2 Chronicles 25:16
And it happened [that] while he was speaking to him, he said to him, "Have we appointed you as a counselor to the king? Stop--{why should you be killed}?" So the prophet stopped and said, "I know that God has determined to destroy you, because you have done this and have not listened to my advice."
Isaiah 6:9
And he said, "Go and say to this people, 'Keep on listening and do not comprehend! And keep on looking and do not understand!'
Romans 9:18
Consequently therefore, he has mercy on whomever he wishes, and he hardens whomever he wishes.

As the lord

Joshua 11:12
And Joshua captured all the cities of these kings, and all their kings, and he utterly destroyed them with {the edge of the sword}, as Moses the servant of Yahweh commanded.
Deuteronomy 20:16
But from the cities of these peoples that Yahweh your God [is] giving to you as an inheritance, you shall not let anything live that breathes.