Joshua 11:20

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

Deuteronomy 20:16-17

But of the cities of these peoples, that Jehovah thy God giveth thee for an inheritance, thou shalt save alive nothing that breatheth;

Exodus 4:21

And Jehovah said unto Moses, When thou goest back into Egypt, see that thou do before Pharaoh all the wonders which I have put in thy hand: but I will harden his heart and he will not let the people go.

Deuteronomy 7:16

And thou shalt consume all the peoples that Jehovah thy God shall deliver unto thee; thine eye shall not pity them: neither shalt thou serve their gods; for that will be a snare unto thee.

Romans 9:18

So then he hath mercy on whom he will, and whom he will be hardeneth.

Exodus 9:16

but in very deed for this cause have I made thee to stand, to show thee my power, and that my name may be declared throughout all the earth.

Exodus 14:17

And I, behold, I will harden the hearts of the Egyptians, and they shall go in after them: and I will get me honor upon Pharaoh, and upon all his host, upon his chariots, and upon his horsemen.

Deuteronomy 2:30

But Sihon king of Heshbon would not let us pass by him; for Jehovah thy God hardened his spirit, and made his heart obstinate, that he might deliver him into thy hand, as at this day.

Joshua 11:12-15

And all the cities of those kings, and all the kings of them, did Joshua take, and he smote them with the edge of the sword, and utterly destroyed them; as Moses the servant of Jehovah commanded.

Judges 14:4

But his father and his mother knew not that it was of Jehovah; for he sought an occasion against the Philistines. Now at that time the Philistines had rule over Israel.

1 Samuel 2:25

If one man sin against another, God shall judge him; but if a man sin against Jehovah, who shall entreat for him? Notwithstanding, they hearkened not unto the voice of their father, because Jehovah was minded to slay them.

1 Kings 12:15

So the king hearkened not unto the people; for it was a thing brought about of Jehovah, that he might establish his word, which Jehovah spake by Ahijah the Shilonite to Jeroboam the son of Nebat.

1 Kings 22:20-23

And Jehovah said, Who shall entice Ahab, that he may go up and fall at Ramoth-gilead? And one said on this manner; and another said on that manner.

2 Chronicles 25:16

And it came to pass, as he talked with him, that the king'said unto him, Have we made thee of the king's counsel? forbear; why shouldest thou be smitten? Then the prophet forbare, and said, I know that God hath determined to destroy thee, because thou hast done this, and hast not hearkened unto my counsel.

Isaiah 6:9-10

And he said, Go, and tell this people, Hear ye indeed, but understand not; and see ye indeed, but perceive not.

Romans 9:22-23

What if God, willing to show his wrath, and to make his power known, endured with much longsuffering vessels of wrath fitted unto 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 Jehovah said unto Moses, When thou goest back into Egypt, see that thou do before Pharaoh all the wonders which I have put in thy hand: but I will harden his heart and he will not let the people go.
Exodus 9:16
but in very deed for this cause have I made thee to stand, to show thee my power, and that my name may be declared throughout all the earth.
Deuteronomy 2:30
But Sihon king of Heshbon would not let us pass by him; for Jehovah thy God hardened his spirit, and made his heart obstinate, that he might deliver him into thy hand, as at this day.
Judges 14:4
But his father and his mother knew not that it was of Jehovah; for he sought an occasion against the Philistines. Now at that time the Philistines had rule over Israel.
1 Samuel 2:25
If one man sin against another, God shall judge him; but if a man sin against Jehovah, who shall entreat for him? Notwithstanding, they hearkened not unto the voice of their father, because Jehovah was minded to slay them.
1 Kings 12:15
So the king hearkened not unto the people; for it was a thing brought about of Jehovah, that he might establish his word, which Jehovah spake by Ahijah the Shilonite to Jeroboam the son of Nebat.
1 Kings 22:20
And Jehovah said, Who shall entice Ahab, that he may go up and fall at Ramoth-gilead? And one said on this manner; and another said on that manner.
2 Chronicles 25:16
And it came to pass, as he talked with him, that the king'said unto him, Have we made thee of the king's counsel? forbear; why shouldest thou be smitten? Then the prophet forbare, and said, I know that God hath determined to destroy thee, because thou hast done this, and hast not hearkened unto my counsel.
Isaiah 6:9
And he said, Go, and tell this people, Hear ye indeed, but understand not; and see ye indeed, but perceive not.
Romans 9:18
So then he hath mercy on whom he will, and whom he will be hardeneth.

As the lord

Joshua 11:12
And all the cities of those kings, and all the kings of them, did Joshua take, and he smote them with the edge of the sword, and utterly destroyed them; as Moses the servant of Jehovah commanded.
Deuteronomy 20:16
But of the cities of these peoples, that Jehovah thy God giveth thee for an inheritance, thou shalt save alive nothing that breatheth;

American Standard Version Public Domain