आगमे विश्वासटिप्पन्यः

In the dharma literature, four actions
are deemed such heinous offenses that
the person performing them becomes
an outcast from society. These four
actions are murdering a brahmin
(brahmahatya), stealing a brahmin’s
gold (steya), drinking liquor (surapana), and adultery with the wife of
one’s guru (gurutalpaga). Aside from
expulsion from society, another indication of the gravity of these acts was that
their penalties were so severe that they
normally ended in death, and in some
cases this outcome was specifically prescribed. In addition to prescribing such
punishments for the actual offenders,
the dharma literature also prescribed
expulsion for anyone who knowingly
associated with such people for a period
longer than one year.