Proverbs 10:32

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

Ecclesiastes 12:10

The Preacher sought to find out acceptable words, and that which was written blamelessly, words of truth.

Proverbs 2:12

to deliver you from the way of evil, from the men who speak 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 about lying in wait for blood, but the speech of the upright rescues them.

Proverbs 12:18

There is one who speaks rashly like the piercing of a sword, but the tongue of the wise heals.

Proverbs 15:2

The tongue of the wise commends knowledge, but the mouth of fools gush out folly.

Proverbs 15:28

The heart of the righteous weighs answers, but the mouth of the wicked gushes out evil.

Proverbs 18:6-8

A fool's lips come into strife, and his mouth invites beatings.

Ecclesiastes 10:12

The words of a wise man's mouth are gracious; but a fool is swallowed by his own lips.

Daniel 4:27

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

Titus 2:8

and soundness of speech that can't be condemned; that he who opposes you may be ashamed, having no evil thing to say about us.

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 out acceptable words, and that which was written blamelessly, words of truth.
Daniel 4:27
Therefore, O king, let my counsel be acceptable to you, and break off your sins by righteousness, and your iniquities by showing mercy to the poor; if there may be a lengthening of your tranquility.
Titus 2:8
and soundness of speech that can't be condemned; that he who opposes you may be ashamed, having no evil thing to say about us.

General references

Matthew 15:18
But the things which proceed out of the mouth come out of the heart, and they defile the man.