Matthew 12:35

a good man out of the good treasure produces good things: and an evil man, out of the evil treasure, produces evil things.

Ephesians 4:29

let no obscene language defile your mouth, use only such as tends to edification, that it may be beneficial to the hearers.

Colossians 4:6

let an air of modesty appear in all your discourse; and let it be seasoned with discretion, in making a proper reply, when you are call'd into question.

Treasury of Scripture Knowledge

Summary

The mouth of the righteous speaketh wisdom, and his tongue talketh of judgment.

Bible References

General references

Matthew 12:35
a good man out of the good treasure produces good things: and an evil man, out of the evil treasure, produces evil things.
Ephesians 4:29
let no obscene language defile your mouth, use only such as tends to edification, that it may be beneficial to the hearers.
Colossians 4:6
let an air of modesty appear in all your discourse; and let it be seasoned with discretion, in making a proper reply, when you are call'd into question.