Sir 28:14

“The tongue, by nature restless, does no small amount of harm among mortals so that either it squanders an opportunity by saying too much or wreaks havoc by not saying anything for long periods of silence. But when do quarrels ignite, if the tongue is checked? Or what space is there for enmities where the poison of words has ceased? Indeed, the malicious tongue always acts in this way: it sows quarrels, incites hatreds and leads to death, as Solomon says on the matter: "The tongue has upset the peace of many. It has destroyed cities and ruined families." They certainly are mistaken who think that there is nothing stronger than iron, or more deadly than poison: although these things by their nature would have a particular inclination to cause death, they nonetheless give way when compared with words. Indeed, nothing that is within one's power is more harmful or malicious than the tongue, once it is aroused.”