"The punishment of a liar is that, even when he speaks the truth, none believe him. " ~~ Talmud, Sanhedrin
"A fool is his own informer." ~~ Yiddish Proverb
"Accustom not your lips to use obscene speech! " ~~ Ben Sira 23:13
"Hold your tongue as you would hold your money! " ~~ Mivchar Hapeninim
"I was so self-conscious, every time football players went into a huddle, I thought they were talking about me." ~~ Jackie Mason
"Slander is worse than idolatry. " ~~ Shocher Tov
"Did we realize the inner meaning of each word we utter, our time would suffice for but a few words. " ~~ Jacob Klatzkin
"Let your ears hear what your lips speak! " ~~ Genesis (Bereshit) R.
"Condemn not your fellow until you stand in his place! " ~~ Avot 2:4
"A bird you set free you may catch again, but a word that escapes your lips will not return. " ~~ Mishle Yehoshua
"The world goes on because of those who close their lips when they meet hostility from others." ~~ Nachman of Bratslav
"Even if all of a slander is not believed, half of it is." ~~ Midrash Genesis R. 56:4