Ephesians
King James Version (KJV)

“Let no corrupt communication proceed out of your mouth, but that which is good to the use of edifying, that it may minister grace unto the hearers.”
King James Version (KJV)
4:29 But that which is good - Profitable to the speaker and hearers. To the use of edifying - To forward them in repentance, faith, or holiness. That it may minister grace - Be a means of conveying more grace into their hearts. Hence we learn, what discourse is corrupt, as it were stinking in the nostrils of God; namely, all that is not profitable, not edifying, not apt to minister grace to the hearers.
Eph 4:29 Let no corrupt communication proceed out of your mouth. What is rotten. Anything that will demoralize others. Obscene, licentious, or immoral language is forbidden. All that the Christian speaks should be that which is good to the use of edifying, building the hearers up in Christ.