Beta Israel practised a Judaism that separated from the rest of the Jewish world before rabbinic literature reached Ethiopia, which is why the label pre-rabbinic is used and why it is contested. Their scripture is the Orit — the Torah plus Joshua, Judges and Ruth — in Ge'ez, alongside Jubilees, Enoch, and works with no parallel elsewhere in Judaism, and their prayers were led by kessim rather than rabbis. Their practice included strict Sabbath observance with a body of Sabbath literature of its own, ritual purity rules considerably stricter than the rabbinic ones including separation huts for menstruation and childbirth, monastic ascetics, and a sacrificial practice that continued into the modern era. They kept no Talmud, no Purim in the standard form, no Hanukkah, and no Oral Law. Israel's Chief Rabbinate ruled them Jewish in 1973 on Sephardi chief rabbi Ovadia Yosef's determination that they descend from the tribe of Dan, and then in practice required many immigrants to undergo giyur lechumra, a conversion performed out of doubt, which the community protested publicly and at length in 1985 and largely defeated. The kessim have been steadily displaced by Israeli-trained rabbis, and whether the Ethiopian rite survives its own absorption is an open question inside the community.