Illustration Credit: Elad Lifshitz, Dov Abramson Studio

When a person had צָרַעַת (tzara’at), they needed to live outside the community (Vayikra 13:46). Why was this necessary?

Hazal explain that one of the causes of tzara’at was speaking לָשׁוֹן הָרָע (lashon hara, gossip and slander). By speaking improperly, a person might have made other people feel ashamed and alone. So tzara’at makes them get separated, too. The punishment fits the crime (Arakhin 16b).

Bekhor Shor says the person had to live alone to make sure that they didn’t spread tzara’at to other people.

It’s likely that what was contagious was the person’s טֻמְאָה (tum’ah, impurity), not their tzara’at. A person with tzara’at could spread tum’ah to other things or people under the same roof, so that could explain the need for isolation.