Who Is A Jew? Traditional Sources

(12) Wherever there is [a valid] betrothal and no sin, the child follows the male [with regard to familial status]. Which is this? This is a Kohenet, a Levite woman, or an Israelite woman who married a Kohen, a Levite or an Israelite. Wherever there is [a valid] betrothal and there is a sin, the child follows the defective one. Which is this? This is a widow married to the Kohen Gadol [High Priest], a divorcee or a chalutzah [the widow of a childless man released from the obligation of levirate marriage by a ceremony performed by her brother-in-law] [married] to an ordinary Kohen, a mamzeret [the female offspring of certain prohibited relationships who may not marry into the general Jewish population] or a Netina [female Gibeonite] to an Israelite, a female Israelite to a mamzer or Netina. [With] any [woman] for whom there is no betrothal to him, but there is betrothal to others, the child is a mamzer. Which is this? This is one who has sexual intercourse with any one of the forbidden sexual relations [mentioned] in the Torah. Any [woman] for whom there is no betrothal either to him or to others, the child is like her. Which is this? This is the child of a [non-Jewish] maidservant or a non-Jewish woman.

(19) If a non-Jew or a slave cohabit with a female mamzer, the offspring is a mamzer. If they cohabit with a Jewish woman, whether she is single or married, the offspring is permitted [to marry into the congregation], but is considered damaged with regard to marrying a kohen.

Rab Judah said in the name of R. Assi: If at the present time a heathen betroths [a daughter in Israel], note must be taken of such betrothal since it may be that he is of the ten tribes. But, surely, anything separated [from a heterogeneous group] is regarded as having been separated from the majority! — [R. Assi's statement refers] to places where they have settled;… When I mentioned the matter in the presence of Samuel he said to me, 'Theydid not move from there until they had declared them to be perfect heathens; as it is said in the Scriptures, They have dealt treacherously against the Lord, for they have begotten strange children

...When he comes up after his ablution he is deemed to be an Israelite in all respects'. In respect of what practical issue? — In that if he retracted and then betrothed the daughter of an Israelite he is regarded as a non­conforming Israelite and his betrothal is valid

(6) The following are the people who have no share in the World to Come, but are cut off and lost and judged for the magnitude of their wickedness and sins forever and ever: Sectarians (minim); Heretics (apikorsin - from epicurean); Deniers of Torah; Deniers of Resurrection; [Deniers] of the coming of the Messiah; Apostates; those who lead the masses into sin; those who separate from the community; those who separate from the ways of the community; those who sin with a high hand in public like Jehoiakim; Collaborators [with the government]; those who bring fear upon the community but not for the sake of Heaven; Murderers; Gossipers; and those who reverse their circumcision.

(7) There are five [types] who are called "sectrarians" (minnim): One who says that there is no god and no director of the world. One who says that there is a director, but there are two or more. One who says that there is one master but that he has a body and a being with a form. And similarly one who says that He is not the first alone and creator of all. And similarly one who worships a star or constellation, and similar things, in order to intercede between him and the Master of Worlds. Any one of these five is considered a "min" - sectarian.

(8) There are three that are called "heretics" (apikorsin): One who says that there is no such thing as prophecy and there is no such thing as information that is passed from the Creator to the heart of man. And one who denies the prophecy of Moses, our teacher. And one who says that the Creator does not know man's actions. Any one of these is considered an "apikores" - heretic. Three are deniers of the Torah: One who say that the Torah is not from God, even one verse, even one letter, if he says that Moses said it on his own, that is denying the Torah. And similarly, one who denies the interpretation of the Torah, that is the Oral Torah, and denies its imparters, such as Tzaddok and Beothius. And one who says that the Creator switched this commandment for another one, and that the Torah has been voided, although it is from God, such as the Haggarites (Arabs). Any one of these is a denier of the Torah.

(9) There are two that are Jewish apostates: One who rebels against a single mitzvah, and one who rebels against the entire Torah. Someone who rebels against a single mitzvah – this is a person who accustoms himself to do a certain sin intentionally and becomes notorious for it, even if it were one of the minor sins, such as wearing sha’atnez or shaving the corners [of one’s beard], so that it is as if, for him, that mitzvah has been erased from the world. Such a person has rebelled against that particular thing, meaning that he does it spitefully. Someone who rebels against the entire Torah – such as those who return to the religion of idolaters during a time of oppression, and cling to them and say: How does it benefit me to cling to Israel who are lowly and pursued? It is better for me to cling to those whose hands are forceful. Such a person has rebelled against the entire Torah.