Proverbs 10:32

The lips of a righteous man knows what is acceptable, but the mouth of the wicked [is] perverseness.

Ecclesiastes 12:10

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

Proverbs 2:12

to deliver thee 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 lay in wait for blood, but the mouth of the upright shall deliver them.

Proverbs 12:18

There is he who speaks rashly like the piercings of a sword, but the tongue of the wise is health.

Proverbs 15:2

The tongue of the wise utters knowledge rightly, but the mouth of fools pours out folly.

Proverbs 15:28

The heart of a righteous man meditates 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 stripes.

Ecclesiastes 10:12

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

Daniel 4:27

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

Titus 2:8

sound speech, irreproachable, so that the man of opposition may be ashamed, having nothing bad 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 uprightly--words of truth.
Daniel 4:27
Therefore, O king, let my counsel be acceptable to thee, and break off thy sins by righteousness, and thine iniquities by showing mercy to the poor, if there may be a lengthening of thy tranquility.
Titus 2:8
sound speech, irreproachable, so that the man of opposition may be ashamed, having nothing bad to say about us.

General references

Matthew 15:18
But the things coming out of the mouth come forth from the heart, and those things defile the man.