Proverbs 10:32

The lips of the righteous know what is acceptable: but the mouth of the wicked, what is perverse.

Ecclesiastes 12:10

The preacher sought to find acceptable words: and that which was written was upright, even words of truth.

Proverbs 2:12

To deliver you from the way of the evil man, from the man that speaks perverse things;

Proverbs 11:11

By the blessing of the upright the city is exalted: but it is overthrown by the mouth of the wicked.

Proverbs 12:6

The words of the wicked are to lie in wait for blood: but the mouth of the upright shall deliver them.

Proverbs 12:18

There is one that speaks like the piercings of a sword: but the tongue of the wise brings health.

Proverbs 15:2

The tongue of the wise uses knowledge aright: but the mouth of fools pours out foolishness.

Proverbs 15:28

The heart of the righteous studies to answer: but the mouth of the wicked pours out evil things.

Proverbs 18:6-8

A fool's lips enter into contention, and his mouth calls for blows.

Ecclesiastes 10:12

The words of a wise man's mouth are gracious; but the lips of a fool will swallow him up.

Daniel 4:27

Therefore, O king, let my counsel be acceptable unto you, and break off your sins by practicing righteousness, and your iniquities by showing mercy to the poor; if it may be a lengthening of your tranquility.

Titus 2:8

Sound speech, that cannot be condemned; that he that is an opponent may be ashamed, having no evil thing to say of you.

Treasury of Scripture Knowledge

Summary

The lips of the righteous know what is acceptable: but the mouth of the wicked speaketh frowardness.

General references

Bible References

Know

Ecclesiastes 12:10
The preacher sought to find acceptable words: and that which was written was upright, even words of truth.
Daniel 4:27
Therefore, O king, let my counsel be acceptable unto you, and break off your sins by practicing righteousness, and your iniquities by showing mercy to the poor; if it may be a lengthening of your tranquility.
Titus 2:8
Sound speech, that cannot be condemned; that he that is an opponent may be ashamed, having no evil thing to say of you.

General references

Matthew 15:18
But those things which proceed out of the mouth come forth from the heart; and they defile the man.