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
Ashkenazi Hebrew from Spain in 1492 (or before) the Sephardic pronunciation of the vowels became standard in all these countries, ironing out any differences that previously existed. This makes it harder to adjudicate between the different theories on the relationship between today's pronunciation systems and those of ancient times. Leopold Zunz believed that the Ashkenazi pronunciation was derived from that of Palestine in Geonic times (7th–11th centuries CE), while the Sephardi pronunciation was derived from that of Babylonia. This theory was supported by the fact that, in some respects, Ashkenazi Hebrew resembles the western dialect of Syriac while Sephardi Hebrew resembles the