O army of God! Beware lest ye harm anysoul, or make any heart to sorrow; lest yewound any man with your words, be heknown to you or a stranger, be he friend orfoe. Pray ye for all; ask ye that all beblessed, all be forgiven. Beware, beware,lest any of you seek vengeance, even against one who is thirsting for your blood.Beware, beware, lest ye offend the feelingsof another, even though he be an evil-doer,and he wish you ill.
~ Abdu'l-Baha, Selections from the Writings of Abdu'l-Baha, p. 73

Let the words of my mouth, and themeditation of my heart, be acceptablein thy sight, O LORD, my strength,and my redeemer.
~ Psalms 19:14 Holy Bible, King James Version

...and from Native American teachings:"
If those bad words come, I let them come in one ear and go out the other.I never let them come out of my mouth.If a bad word comes in your ear and thencomes out of your mouth, it will gosomeplace and hurt somebody. If I didthat, that hurt would come back twice ashard on me."
~ Wallace Black Elk, LAKOTA"Great Spirit, today, let no words come from my lips that would hurt another." ~ from White Bison's Elder Meditations