If you argue your case with a neighbor, do not betray another man's confidence, or he who hears it may shame you and you will never lose your bad reputation.

Basically, what they're saying is that if you're fighting, which you shoundn't be doing anyway, don't give away secrets to you're avantage, cause, fist of all, that's just wrong. Second, like he state, the guy you told, or the people that may happen to hear are gonna tell on you an you're never gonna lose your bad reputation. you're always gonna beknown as the guy who couln't keep a secret. In my house they say, 'You've got a hole in your treasure chest!'