Isaiah 1:20

But if your hearts are turned against me, I will send destruction on you by the sword; so the Lord has said.

Isaiah 40:5

And the glory of the Lord will be made clear, and all flesh will see it together, for the mouth of the Lord has said it.

Isaiah 58:14

Then the Lord will be your delight; and I will put you on the high places of the earth; and I will give you the heritage of Jacob your father: for the mouth of the Lord has said it.

Numbers 23:19

God is not a man, to say what is false; or the son of man, that his purpose may be changed: what he has said, will he not do? and will he not give effect to the words of his mouth

Micah 4:4

But every man will be seated under his vine and under his fig-tree, and no one will be a cause of fear to them: for the mouth of the Lord of armies has said it.

Titus 1:2

In the hope of eternal life, which was made certain before eternal time, by the word of God who is ever true;

Leviticus 26:33

And I will send you out in all directions among the nations, and my sword will be uncovered against you, and your land will be without any living thing, and your towns will be made waste.

1 Samuel 12:25

But if you still do evil, destruction will overtake you and your king.

1 Samuel 15:29

And further, the Glory of Israel will not say what is false, and his purpose may not be changed: for he is not a man, whose purpose may be changed.

2 Chronicles 36:14-16

And more than this, all the great men of Judah and the priests and the people made their sin great, turning to all the disgusting ways of the nations; and they made unclean the house of the Lord which he had made holy in Jerusalem.

Isaiah 3:11

Unhappy is the sinner! for the reward of his evil doings will come on him.

Isaiah 3:25

Your men will be put to the sword, and your men of war will come to destruction in the fight.

Isaiah 65:12

Your fate will be the sword, and you will all go down to death: because when my voice came to you, you made no answer; you did not give ear to my word; but you did what was evil in my eyes, desiring what was not pleasing to me.

Hebrews 2:1-3

For this reason there is the more need for us to give attention to the things which have come to our ears, for fear that by chance we might be slipping away.

Treasury of Scripture Knowledge

Summary

But if ye refuse and rebel, ye shall be devoured with the sword: for the mouth of the LORD hath spoken it.

Bible References

If ye refuse

Isaiah 3:11
Unhappy is the sinner! for the reward of his evil doings will come on him.
1 Samuel 12:25
But if you still do evil, destruction will overtake you and your king.
2 Chronicles 36:14
And more than this, all the great men of Judah and the priests and the people made their sin great, turning to all the disgusting ways of the nations; and they made unclean the house of the Lord which he had made holy in Jerusalem.
Hebrews 2:1
For this reason there is the more need for us to give attention to the things which have come to our ears, for fear that by chance we might be slipping away.

For the mouth

Isaiah 40:5
And the glory of the Lord will be made clear, and all flesh will see it together, for the mouth of the Lord has said it.
Isaiah 58:14
Then the Lord will be your delight; and I will put you on the high places of the earth; and I will give you the heritage of Jacob your father: for the mouth of the Lord has said it.
Leviticus 26:33
And I will send you out in all directions among the nations, and my sword will be uncovered against you, and your land will be without any living thing, and your towns will be made waste.
Numbers 23:19
God is not a man, to say what is false; or the son of man, that his purpose may be changed: what he has said, will he not do? and will he not give effect to the words of his mouth
1 Samuel 15:29
And further, the Glory of Israel will not say what is false, and his purpose may not be changed: for he is not a man, whose purpose may be changed.
Titus 1:2
In the hope of eternal life, which was made certain before eternal time, by the word of God who is ever true;

General references

Exodus 9:2
For if you will not let them go, but still keep them in your power,
Leviticus 26:23
And if by these things you will not be turned to me, but still go against me;
Deuteronomy 11:28
And the curse if you do not give ear to the orders of the Lord your God, but let yourselves be turned from the way which I have put before you this day, and go after other gods which are not yours.
Deuteronomy 15:5
If only you give ear to the voice of the Lord your God, and take care to keep all these orders which I give you today.
Ezekiel 39:24
In the measure of their unclean ways and their sins, so I did to them; and I kept my face covered from them.

Basic English, produced by Mr C. K. Ogden of the Orthological Institute - public domain