Zugot ("pairs"): Five pairs (zugot) of sages from consecutive generations, who lived during a period of around 100 years towards the end of the Second Temple era. (142BCE –
c. 40BCE)
Amoraim ("expounders"): The sages of the
Talmud who were active during the end of the era of the sealing of the Mishnah, and until the times of the sealing of the Talmud (220CE – 500CE). The Amoraim sages were active in two areas, the Land of Israel, and
Babylon. In addition to the
Babylonian Talmud and the
Jerusalem Talmud, their writings were preserved in midrashs such as
Midrash Rabba.
Savoraim ("reasoners"): The sages of Beth midrash (Torah study places) in Babylon from the end of the era of the Amoraim (5th century) and until the beginning of the era of the
Geonim (from the end of the 6th century or the midst of the 7th century).
Chazal's authority
Until the end of the Savoraim era, Chazal had the authority to comment on the Torah according to the
Talmudical hermeneutics standards required by the
Law given to Moses at Sinai,[2] sometimes even expounding a word or phrase outside its plain and ordinary sense. Nowadays in
Orthodoxy, this authority is not delegated to the current generation's sages, and thus the
Torah can not be commentated on, in matters concerning the halakha ("Jewish Law"), if it contradicts Chazal's commentary.
Until the middle of the Tannaim era, when there was a
Sanhedrin (a High Court of
Jewish law), Chazal had also the authority to decree restrictions and to enact new religious regulations, in any matter they saw fit, concerning issues that were not included in the written Torah, or were not delivered at Mount Sinai. These rabbinical mitzvot ("commandments") include the holidays of
Purim and
Hanukkah, the laws of muktzeh ("set-aside items") on
Shabbat, the
ritual washing of one's hands (netilat yadayim) before eating bread, the construction of eruvim (liminal gateways), and the institution of the current schedule of daily prayer services – shacharit (morning prayer), mincha (afternoon prayer), and ma'ariv (evening prayer).