Basil of Caesarea

Anger causes tongues to become unbridled and speech unguarded. Physical violence, acts of contempt, reviling, accusations, blows and other bad effects too numerous to recount are born of anger and indignation.

If you love life, fulfill the commandment of life. “The one who loves me,” said Jesus, “keeps my commandments,” and the first commandment is this: “Keep your tongue from evil, and your lips from speaking guile.” For the sin which is caused by the tongue is very active and many-sided, being active in wrath, lust, hypocrisy, judgment and deception. Do we need to recall the many names which are given to sins of the tongue? For from it come slanders, coarse jokes, idiocies, irrelevant accusations, bitterness, swearing, false witness—the tongue is the creator of all these evil things and more.