“He must sit in isolation, alone outside the camp.”
~ Leviticus 13:46
Although there are several forms of spiritual impurity, only Tzara’as requires the afflicted to be separated from the community to get purified.
This affliction comes from slander. The quarrels caused by this person’s words made friends separate and marriages split. So just as he caused others to be alone, so too he should be alone.
But more than tit-for-tat, this process is essential for genuine growth, because you can’t really change until you’ve personally felt the pain you’ve caused.