Family Relationships: Birth, Marriage, and Lasting Prohibitions

An ervah is a woman whose relationship to him falls within the Torah’s category of arayos, such as the prohibited family relationships listed here. This is a specific category; not every Torah prohibition concerning marriage has this status.

Kiddushin, also called erusin, establishes the first stage of a binding Jewish marriage; it is more than an engagement. Nisuin completes the marriage. The family prohibitions discussed here begin with kiddushin, even before nisuin or marital relations.

In these cases, the family prohibition arises through a relative’s marriage. Once established, it continues after divorce or the husband’s death.

The exception concerns yibbum, the Torah’s provision for the widow of a man who died without descendants. Although the Hebrew says “left no son,” the exception requires that the deceased leave no surviving descendants: neither a son nor a daughter, nor descendants of either. It applies only when the other requirements of yibbum are satisfied, including that the deceased and surviving brother share a father. It does not give general permission to marry a brother’s former wife.

The precise distinction between different kinds of paternal uncles is explained in the next halachah.

The additional prohibition of adultery applies while she remains married to the relative. If she has already been divorced, her former husband’s being alive does not make her a married woman; the lasting family prohibition nevertheless remains.

Here, “two liabilities” means two separate sin-offerings for an inadvertent transgression, when the requirements for those offerings are met. It does not mean that an intentional transgression is resolved by bringing offerings.

An inadvertent transgression—shogeg—can occur when someone is unaware of the relevant facts or does not know that the act is prohibited. It does not necessarily mean that the physical act itself happened accidentally.

One act can violate both prohibitions because they take effect together: the same kiddushin make her both a married woman and the wife of his relative.

His mother falls under two separate family prohibitions: the prohibition against one’s mother and the prohibition against one’s father’s wife. His father’s death removes neither prohibition.

These are the two family prohibitions that apply in both periods. If his father is alive and she remains married to him, there is also a third prohibition: relations with a married woman. When the requirements for sin-offerings are met, the separate prohibitions require separate offerings.

Sharing either biological parent establishes the brotherhood relevant to this prohibition. It does not matter whether either brother was born to married parents.

This prohibition is broader than the brotherhood required for yibbum. A maternal brother’s wife is forbidden, but sharing only a mother does not create a yibbum exception.

Here, the father and the uncle share a mother but do not share a father. The uncle’s wife is forbidden as a shniyah: an additional relative prohibited by the Sages as a safeguard around the Torah’s prohibited relationships.

Thus, the Torah prohibition against the wife of one’s father’s brother applies when the father and uncle share a father. The wife of the father’s maternal half-brother is also forbidden, but on a Rabbinic level. See Hilchos Ishus 1:5.

A sister who shares either biological parent is included in the prohibition. The parents’ marital status does not change that relationship. The verse includes both a sister born within marriage and one born outside marriage.

The words “your father’s offspring” identify the relationship: she is a daughter born to his father and his father’s wife. She is therefore also his biological sister.

His father’s marriage does not turn the woman’s daughter from another man into his biological sister. Assuming no separate prohibition applies, he may marry her.

The woman herself becomes forbidden to him because she married his father. Her daughter from another man does not acquire the status of his sister through that marriage.

The question returns to the first case, in which the daughter is his father’s biological child. The prohibition against one’s sister already covers her. The additional verse establishes a second prohibition when she is also the daughter of his father’s wife. The next halachah explains the resulting distinction.

The same woman is both his sister and the daughter of his father’s wife. When an inadvertent transgression meets the requirements for sin-offerings, the two prohibitions require two offerings.

The father has a daughter through relations outside marriage. The next clause concerns his son having relations with that daughter—his paternal sister.

She is fully his sister even though her parents were not married. However, because her mother was not his father’s wife, the additional prohibition against a father’s wife’s daughter does not apply.

The same distinction applies whether the father’s relations with the mother involved rape or seduction. “Only” identifies the family prohibition applicable here; the relationship remains forbidden.

The aunt need not be his mother’s full sister. A sister who shares only one parent with his mother is also included. The biological relationship establishes the prohibition regardless of whether the parents were married.

The prohibition concerns the father’s biological sister herself. It applies whether she shares his father’s father or his father’s mother.

This differs from Halachah 2’s distinction concerning the wife of the father’s brother. A parent’s biological sister is a Torah-level ervah through either parental connection; the wife of the father’s maternal half-brother is prohibited as a shniyah.

The prohibition follows the biological relationship. It makes no difference whether he was married to her mother.

The Torah expressly prohibits a granddaughter whose relationship to him comes through his daughter. That prohibition already presupposes that the daughter herself is forbidden. The Rambam therefore treats the daughter’s prohibition as though the Torah had stated it explicitly.

Here the Rambam is addressing a technical distinction concerning how a law is expressed or derived. He is emphasizing that this prohibition has the standing of an expressly stated Torah law.

Two distinct prohibitions apply to the same person: she is his biological daughter, and she is his wife’s daughter. When the transgression is inadvertent and the requirements for sacrificial liability are met, he must bring two sin-offerings. This does not mean that two executions are imposed for an intentional transgression.

These prohibitions begin with kiddushin, the first stage of marriage. They do not depend on completing nisuin, the second stage, or on marital relations.

Once established, the prohibitions continue even if the marriage ends through divorce or death. Halachah 8 will explain that the wife’s death changes the punishment, although it does not remove the prohibition.

The six relatives include three in the generations above his wife and three in the generations below her. Her daughter and granddaughters are forbidden to him even when they descend from another man.

“Both” means the man and the relative who knowingly and willingly participates in the transgression. His wife is not punished for their conduct.

As with the capital laws discussed in Chapter 1, judicial execution requires all the prescribed conditions, including valid witnesses and warning. Divorce does not remove the punishment described here while his former wife remains alive.

“Her” refers to any of the six relatives listed in the preceding halachah.

According to the Rambam, the intentional transgression remains punishable by kareis, a punishment imposed by Heaven, commonly translated as spiritual excision. The wife’s death removes the judicial death penalty; it does not permit the relationship.

The verse is Vayikra 20:14.

The verse’s plural wording establishes a condition: his wife and the relative must both be alive for this judicial punishment to apply. It does not mean that his innocent wife is executed.

In the case under discussion, his wife has died and her relative is still alive. The phrase does not require that both women have died.

A wife’s sister differs from the six relatives listed earlier. Those six remain forbidden after the wife’s death. The prohibition against her sister ends when the wife dies, provided no other prohibition applies.

Divorce does not end this prohibition. Even after divorcing his wife, he may not marry her sister while his former wife is alive. The Torah expressly limits this prohibition to the wife’s lifetime: Vayikra 18:18.

The prohibition includes a full sister and a half-sister through either parent. Whether their parents were married does not change their biological relationship.

The seven women are the six relatives listed in Halachah 7 together with his wife’s sister, discussed in Halachah 9.

The reference to execution or kareis describes the severity of these forbidden relationships when committed intentionally under the relevant conditions. It does not mean that an inadvertent transgression carries those intentional punishments.

His wife has not committed the transgression. His sin with her relative does not, by itself, prohibit continuing his marriage to her.

The Maggid Mishneh explains that this exception concerns a particular case described in Hilchos Gerushin 10:8–10:

A man consecrates a woman, but they have not yet entered full marriage. She travels elsewhere, and he hears that she has died. Relying on that report, he marries her sister. The first woman is then discovered to be alive. In this case, both women require a get, and he may not return to his original bride.

The distinction depends on the stage of the first marriage. If it had reached only erusin, the special restriction applies. If the couple had already completed nisuin, the mistaken marriage to her sister does not prohibit his original wife to him.

Relations alone with his consecrated bride’s sister, without the attempted marriage described here, do not create this exception.

The seven are her mother, her two grandmothers, her daughter, her two granddaughters, and her sister.

These Torah prohibitions arise through kiddushin, which establishes a marriage bond. Relations without kiddushin do not establish that bond and therefore do not create these particular prohibitions against her relatives. Nevertheless, the Sages prohibited marrying these relatives during the original woman’s lifetime, as the Rambam now explains.

Here the Rambam’s description refers to the woman with whom he had illicit relations. It does not require that she be a professional prostitute.

The sequence matters. His earlier relations did not create a marriage bond. Once he marries her relative, however, the original woman becomes an ervah to him through that marriage.

For example, if he marries her daughter, the original woman becomes his mother-in-law. Their previous familiarity, together with opportunities to meet during family visits, could then lead to a severe transgression.

After the original woman’s death, this particular Rabbinic restriction no longer applies.

In his Commentary to the Mishnah, the Rambam describes a suspicion that has been substantiated. This is not a statement that any unsupported accusation establishes the restriction.

Although the Sages prohibited entering this marriage, they did not require dissolving it once it had taken place. This applies even when the earlier relations occurred, rather than only when they were suspected.

The original woman is now an ervah to him through his marriage. The prohibitions against relations and forbidden seclusion with her remain binding.

An ervah here means a woman with whom relations are forbidden under the severe prohibitions discussed in these chapters.

The Rambam requires distance from the setting associated with the suspected relationship. The restriction extends beyond avoiding actual relations or being alone together: he must also avoid the nearby residential surroundings described here.

These restrictions do not mean that the underlying transgression has been established through the testimony required to impose its Torah punishment.

Makkas mardus means lashes administered as a disciplinary measure under Rabbinic authority. They are distinct from the Torah’s prescribed punishment of lashes.

The conduct identified as the reason for this disciplinary punishment is passing her doorway in the circumstances described.

Here, “outside marriage” means that no kiddushin established a marriage bond with either woman. It does not mean merely that the couple had not yet completed nisuin.

“Unrelated women” means women who have no relevant family relationship to him. The word נָכְרִיּוֹת here does not mean non-Jewish women.

The comparison concerns the particular family prohibitions created through marriage. It does not permit the relations or remove any other prohibition that applies.

For example, kiddushin with a woman prohibits her daughter to him. Relations with that woman without kiddushin do not create this particular Torah prohibition against her daughter.

“Marriage” here includes the bond established through kiddushin, as Halachah 7 explained. The Rabbinic restrictions discussed in Halachah 11 still apply.

For example, if a man’s father had relations with a woman without marrying her, the next clause discusses whether the son may marry that woman.

Those relations alone do not make her his relative’s wife. They therefore do not create the prohibitions against a father’s wife, son’s wife, brother’s wife, or paternal uncle’s wife. This permission assumes that no independent prohibition applies.

A marriage bond is established through kiddushin. The act of rape or seduction does not itself establish that bond, even though the conduct may involve serious transgressions and other legal consequences.

The prohibition against his father’s wife or his son’s wife does not automatically extend to that woman’s relatives.

For example, if his father marries a woman who has a daughter from another man, that daughter does not become his biological sister merely because their parents married.

Each permission assumes that no separate blood relationship or other prohibition applies.

This means his nephew’s former wife, after the nephew has died or divorced her. While she remains married to the nephew, she is forbidden as a married woman.

The Torah prohibits a brother’s wife, but that family prohibition does not extend to the wife of a brother’s son.

The Rambam is discussing which family relationships prohibit marriage within the legal framework in which a man could have more than one wife.

A wife’s niece is not included among the seven relatives prohibited through marriage. Conversely, marrying the niece does not make her aunt one of those seven prohibited relatives. This statement addresses the family prohibition itself; separate laws governing taking an additional wife must also be observed.

The verse is Yeshayahu 58:7.

This identifies a marriage the Sages commend. It does not require every man to seek a niece as his wife.

The direction of the relationship is essential: the Rambam permits a man to marry his niece. A man marrying his aunt is an entirely different relationship and is forbidden, as explained in Halachah 5.