Semikhah

Semikhah (Hebrew: סמיכה‎, "leaning "), also semichut (Hebrew: סמיכות‎, "ordination"), or semicha lerabbanut (Hebrew: סמיכה לרבנות‎, "rabbinical ordination") is derived from a Hebrew word which means to "rely on" or "to be authorized". It generally refers to the ordination of a rabbi within Judaism. In this sense it is the "transmission" of rabbinic authority to give advice or judgment in Jewish law. Although presently most functioning synagogue rabbis hold semikhah by some rabbinical institution or academy, this was until quite recently not always required, and in fact many Haredi rabbis may not be required to hold a "formal" semikhah even though they may occupy important rabbinical and leadership positions.

Classical semikhah refers to a specific type of ordination that, according to traditional Jewish teaching, traces a line of authority back to Moses and the seventy elders. The line of classical semikhah seems to have died out in the 4th or 5th century CE but it is widely held that the line of Torah conferment remains unbroken. Some believe evidence exists that classical semicha was existent during the 12th century when semuchim from Lebanon and Syria were traveling to Israel in order to pass on semikhah to their students. Others, such as Rav Yisroel of Shklov (1770–1839), believed it may not have been broken at all but that it continued outside of the land of Israel. Today many believe in the existence of an unbroken chain of authority dating back to the time of Moses and Joshua (See "The Unbroken Chain of Torah" below).

A third and distinct meaning of semikhah is the laying of hands upon an offering of a korban ("sacrifice") in the times of the Temple in Jerusalem, see Semicha in sacrifices.