The Chapter on Bad Conduct
AN 4.221 Verbal Conduct Duccaritasutta
"Mendicants, there are these four kinds of bad conduct by way of speech. What four? Speech that’s false, divisive, harsh, or nonsensical. These are the four kinds of bad conduct by way of speech.
There are these four kinds of good conduct by way of speech. What four? Speech that’s true, harmonious, gentle, and thoughtful. These are the four kinds of good conduct by way of speech."