Rabbinical Rules and Laws

In addition to the 613 mitzvot, Jewish law incorporates a large body of rabbinical rules and laws. These are considered just as binding as the mitzvot, although the punishments for violating them are less severe. Another difference is that it is possible, though unlikely, for the rabbinical laws to be changed, but no rabbi can change the Torah mitzvot. The rabbinical portion of halakhah falls into three groups: gezeirah, takkanah, and minhag. A gezeirah is a rule instituted by the rabbis to prevent inadvertent violation of a mitzvah. For instance, it is a mitvah to refrain from work on the Sabbath, but a gezeirah to avoid even the handling of any work instruments on the Sabbath. A takkanah is a law instituted by rabbis that does not derive from the Torah. One example would be the lighting of candles on Hanukkah, a post-biblical holiday. Takkanot can sometimes vary by region: Ashkenazic Jews (who live in Christian nations) accepted a takkanah banning polygamy in c. 1000 CE, while Sephardic Jews (who live in Islamic societies) do not follow such a law. A final type of rabbinical law is a minhag, which is "a custom that evolved for worthy religious reasons and has continued long enough to become a binding religious practice." {3} An example minhag would be the custom of celebrating certain holidays a day longer in the Diaspora than in Israel. The term minhag is sometimes used in a broader sense, to indicate the general custom or way of a particular community. While these are not formalized or universal, it congregants are still encouraged to follow the community minhag.

Video on Jewish rules