Mitzvah is Hebrew for "commandment." The word is used in Judaism to refer to (a) the laws enumerated in the Torah (five books of Moses), or (b) any Jewish law at all. It also is informally used to refer to any admirable deed.

In rabbinic Jewsih terminology "mitzvah" is the general term for a divinely instituted rule of conduct. As such, the divine commandments are divided into (1) mandatory laws and (2) those of a prohibitory character. This terminology rests on the theological construction that God's will is the source of and authority for every moral and religious duty.

In due logical development of this theology, the Rabbis came to assume that the Law comprised 613 commandments, of which 611 are said to have been given through Moses; the first two commandments of the Decalogue were given by the mouth of God Himself. According to R. Ismael only the principal commandments were given on Mount Sinai, the special commandments having been given in the Tent of Meeting. According to R. Akiba they were all given on Mount Sinai, repeated in the Tent of Meeting, and declared a third time by Moses before his death. All divine commandments, however, were given on Mount Sinai, and no prophet could add any new one (Midrash Sifra to Leviticus xxvii. 34; Talmud, Yoma 80a). Many of these laws concern only special classes of people, such as kings or priesthood, Levites or Nazarites, or are conditioned by local or temporary circumstances of the Jewish nation, as, for instance, the agricultural, sacrificial, and Levitical laws.

The Biblical commandments are called in the Talmud "mitzvot de oraita"; commandments of the Law in contradistinction to the rabbinical commandments, "mitvot de rabbanan." Among the latter are: (1) the benediction, or thanksgiving for each enjoyment; (2) ablution of the hands before eating; (3) lighting of the Sabbath lamp; (4) the 'Erub, on preparation for Sabbath transfer; (5) the Hallel liturgy on holy days; (6) the Hanukkah lights; and (7) the reading of the Esther scroll on Purim.

These seven rabbinical commandments are treated like Biblical commandments in so far as, previous to the fulfilment of each, this Benediction is recited: "Blessed be the Lord who has commanded us . . .," the divine command being implied in the general law (Deut. xvii. 11, xxxii. 7; Shab. 23a). Many of the Biblical laws are derived from the Law only by rabbinical interpretation, as, the reading of the Shema' (Deut. vi. 4-7), the binding of the tefillin and the fixing of the mezuzah (ib. 8-9), and the saying of grace after meals (ib. viii. 10).

This term came to express any act of human kindness, such as the burial of the body of an unknown person.

A mitzah which can be fulfilled only by the transgression of another law is considered unlawful.

The proselyte on being initiated into Judaism must be familiarized with commandments both of great and of small import (Yeb. 47b).

According to the teachings of Judaism, all moral laws are virtually and in their ultimate analysis divine commandments. Obedience to the Divine Will is the first requisite of the moral life (see Duty). This is the meaning of the Biblical account of Adam's offense. The first commandment was intended to test his obedience and thus to awaken his moral consciousness.

See also: Torah