(61) The _Mishnah_ is the oral or unwritten law based on the written law contained in the Pentateuch (see chapter I, n. 1). The _Mishnah_, _par excellence_, is the codification made by Judah ha-Nasi (see chapter II, n. 1). It is divided into six orders or sections known as _sedarim_. They are (1) _Zeraim_, "seeds," which contains the laws regarding the cultivation of the land and its products, introduced by a treatise concerning prayer and benedictions (_Berachot_); (2) _Mode_, "festivals," treating of the laws of the Sabbath and the festivals; (3) _Nashim_, "women," regulations concerning marriage and divorce; (4) _Nezikin_, "injuries" or "damages," civil and criminal law; (5) _Kodashim_, "holy things," the laws of sacrifice and of the service of the Temple; and (6) _Tohorot_, "purifications," dealing with the clean and the unclean. Each order is subdivided into treatises (_massektot_), there being in all 63 such subdivisions. The _Mishnah_ is known as the _shas_ ([shin''samech]), which word is formed from the first letters of the words _shishah sedarim_ (six orders). The _Talmud_ is also similarly termed. For a discussion of the name, origin, contents, compilation, etc., of the _Mishnah_, see Mielziner, _Introduction to the Talmud_, p. 4 _et seq._; art. _Mishnah_, in the _Jewish Encyclopedia_ and the authorities cited there; Strack, _Einleitung_, p. 2, 15 _et seq._, 22 _et seq._, and Geiger, _Judaism and its History_, p. 239 _et seq._ (62) At thirteen, the Jewish boy becomes _bar mitzwah_, _i.e._, "a son of commandment." The rites and ceremonies connected with the _bar mitzwah_ of to-day cannot "be clearly traced earlier than the fourteenth century" (Abrahams, _Jewish Life in the Middle Ages_, p. 32). See Schurer, _History_, II, ii, p. 53 and n. 38; Schechter, _Studies_, I, p. 306 _et seq._, and art. _Bar Mitzwah_, in _Jewish Encyclopedia_.