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_.

(63) Lit., "teaching," "learning," "study." Here, it
signifies study for the purpose of elucidating the _Mishnah_.
Some texts read, "for the study of the _Gemara_." The
_Gemara_ (from the Aramaic, meaning "learning," "completion")
is a collection of explanations and discussions on the
_Mishnah_. The word _Talmud_ was afterwards applied to the
_Mishnah_ plus the _Gemara_. There is a translation of the
_Talmud_ in English by Rodkinson, but it is free and
incomplete in parts. See Meilziner, _Introduction to the
Talmud_; Bacher, art. _Talmud_, in _Jewish Encyclopedia_;