Proverbs 10:32

The lips of the righteous know [the] acceptable, but the mouth of the wicked, the perverse.

Ecclesiastes 12:10

The Teacher sought to find delightful words, and he wrote what is upright--truthful words.

Proverbs 2:12

[in order] to deliver you from the way of evil, from a man who speaks devious things--

Proverbs 11:11

By the blessing of the upright, a city will be exalted, but by the mouth of the wicked, it will be overthrown.

Proverbs 12:6

The words of the wicked [are] an ambush of blood, but the mouth of the upright delivers them.

Proverbs 12:18

There is one who speaks rashly, like the thrust of a sword, but the tongue of the wise brings healing.

Proverbs 15:2

The tongue of the wise will dispense knowledge, but the mouth of fools will pour out folly.

Proverbs 15:28

A heart of righteousness will ponder the answer, but a mouth of wickedness will pour out deceit.

Proverbs 18:6-8

The lips of a fool will bring strife, and his mouth calls out for a flogging.

Ecclesiastes 10:12

The wise man [wins] favor by the words of his mouth, but the fool is devoured by his own lips.

Daniel 4:27

Therefore, O king, let my advice be acceptable [to you] and your sin remove with righteousness and your iniquity with having mercy on [the] oppressed, {in case there might be a prolongation of your prosperity}.'"

Titus 2:8

sound message beyond reproach, in order that {an opponent} may be put to shame, [because he] has nothing bad to say concerning 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 Teacher sought to find delightful words, and he wrote what is upright--truthful words.
Daniel 4:27
Therefore, O king, let my advice be acceptable [to you] and your sin remove with righteousness and your iniquity with having mercy on [the] oppressed, {in case there might be a prolongation of your prosperity}.'"
Titus 2:8
sound message beyond reproach, in order that {an opponent} may be put to shame, [because he] has nothing bad to say concerning us.

General references

Matthew 15:18
But the things that come out of the mouth come from the heart, and these defile the person.