Ephesians 4:29
Let no corrupt communication proceed out of your mouth, but that which is good to the use of edifying, that it may minister grace to the hearers.
Torrey's Topical Textbook—AKJV

Colossians 4:6
Let your speech be always with grace, seasoned with salt, that you may know how you ought to answer every man.
Torrey's Topical Textbook—AKJV