Judaism and Mormonism of priests that took place at Israel's Tabernacle, the temple of Solomon, and later temples in Jerusalem (see Exod. 28:40–42, 29:4–9, 29:20–21, 29:29–30, 30:18–21). The Hebrew Bible recounts several cases of polygamy among the ancient Hebrews. One source of polygamy was the practice of levirate marriage, wherein a man was required to marry and support his brother's widow. Ashkenazi Jewry has not practiced polygamy since Rabbenu Gershom's ban in the 11th century "except in exceptional circumstances requiring obtaining in advance the permission of 100 rabbis." Some Sephardi and Mizrahi groups, in particular those from Yemen and Iran (where polygamy is
Ethnoreligious group and ancestral ties. The legal assignement what is an ethnoreligious group can differ from the above given definition. Some ethnoreligious groups' identities are reinforced by the experience of living within a larger community as a distinct minority. Ethnoreligious groups can be tied to ethnic nationalism if the ethnoreligious group possesses a historical base in a specific region. In many ethnoreligious groups emphasis is placed upon religious endogamy, and the concurrent discouragement of interfaith marriages or intercourse, as a means of preserving the stability and historical longevity of the community and culture. Prior to the Babylonian exile the Israelites had already