In 422 BCE, the prophet Ezekiel heard the news of Jerusalem's conquest by a foreign power, as recorded in the biblical Book of Ezekiel (33:21). In Jewish law, a period of mourning (for example, upon the death of a loved one) can begin upon "hearing" the bad news. Some Talmudic commentators thus recommended that the 5th of Tevet be instituted as a public fast day.