Matrilineality in Judaism is the view that people born of a Jewish mother are themselves Jewish. The Torah does not explicitly discuss the conferring of Jewish status through matrilineality. The Tanakh (Hebrew Bible) also provides many examples of Israelite men whose children begotten through foreign women appear to have been accepted as Israelite. In contrast, Jewish oral tradition codified in Mishnah in the 2nd century CE serves as the basis of a shift in Rabbinic Judaism from patrilineal to matrilineal descent. Moreover the concept of matrilineality and matriarchy within Orthodox Judaism is related to the metaphysical concept of the Jewish soul.
The Mishnah (Kiddushin 3:12) states that, to be a Jew, one must be either the child of a Jewish mother or a convert to Judaism, (ger tzedek, "righteous convert"). Orthodox opinion regards this rule as dating from receipt of the Torah at Mount Sinai, but most non-Orthodox scholars regard it as originating either at the time of Ezra (4th Century BCE) or during the period of Roman rule in the 1st–2nd centuries CE, as patrilineal descent is known to have been the standard of Judaism prior to that time.
In the Hellenistic period of the 4th Century BCE – 1st Century CE some evidence may be interpreted to indicate that the offspring of intermarriages between Jewish men and non-Jewish women were considered Jewish; as is usual in prerabbinic texts, there is no mention of conversion on the part of the Gentile spouse. On the other hand, Philo of Alexandria calls the child of a Jew and a non-Jew a nothos (bastard), regardless of whether the non-Jewish parent is the father or the mother.
Karaite Judaism holds that Judaism can only be transmitted through the father, and thus holds a rule of patrilineality. Nevertheless, historical Karaite Jewish and Rabbinical Jewish communities would usually intermarry with each other. Seven marriage contracts involving Karaite and Rabbanite individuals have so far been discovered in the Cairo Genizah. These marriage contracts stipulated the mutual tolerance of those practices in which the Karaites and the Rabbanites differed, with Karaite Judaism arguing that Jewish identity can only be passed through the father, since all Jewish descent in the Tanakh is traced patrilineally.