It is forbidden for us to degrade ourselves by speaking coarsely. Profanity is referred to as nibul peh, which literally means “making the mouth disgusting.” This is because it takes speech, a source of blessing and life, and destroys it. The resulting speech is like a nevela (the carcass of an animal not slaughtered ritually and too disgusting to eat). Since it is well-known that coarse speech is particularly prevalent among soldiers, the Torah specifically admonishes them about this. (See 17:20 below.) When coarse speech includes cursing someone, the speaker is also guilty of belittling a fellow human being.
