In Jewish religious law (halakha), the laws of yichud () prohibit seclusion in a private area of a man and a woman who are not married to each other. Such seclusion is prohibited out of fear that sexual intercourse or other, lesser acts may occur. A person who is present in order to prevent yichud is called a shomer.

The laws of yichud are typically followed in strict Orthodox Judaism. Adherents of Conservative and Reform Judaism do not generally abide by the laws of yichud.

The term "yichud" also refers to a ritual during an Ashkenazi Jewish wedding in which the newly married couple spends a period secluded in a room by themselves. In earlier historical periods, as early as the talmudic era,Abraham P. Bloch, The Biblical and historical background of Jewish customs and ceremonies (KTAV Publishing House, Inc., 1980), p. 32. the couple would have sexual intercourse at this time, but that practice is no longer current.

Source of the prohibition

Deuteronomy 13:7 says: If your very own brother, or your son or daughter, or the wife you love, or your closest friend secretly entices you, saying, 'Let us go and worship other gods, gods that neither you nor your ancestors have known...'

The Talmud gives an explanation to the passage, which is supposed to be a hint of yichud:

Said Rabbi Johanan on the authority of Rabbi Ishmael, Where do we find an allusion to yihud in the Torah? - For it is written: If thy brother, the son of thy mother, entices thee [etc.]: does then only a mother's son entice, and not a father's son? But it is to tell you: a son may be alone with his mother, but not with any other woman interdicted in the Torah.Kiddushin 80b.

The Talmud also claims that after the rape of Tamar, daughter of David, when she was left alone with her half-brother Amnon, David and his high court extended this prohibition to unmarried girls as well. Later, in the times of Shammai and Hillel the Elder, the prohibition was extended to include a non-Jewish woman. These rules are discussed in the Talmud.Rabbi N. D. Dubov: Source Material: Gaining The Necessary Background To Understand The Laws The Laws of Yichud: Permissibility and Prohibition Regarding the Seclusion of a Man and Woman. New York 2006, Sichos in English.

Most rishonim define the prohibition of yichud as a Torah law. Although Maimonides writes that the prohibition of yichud is derived from divrei kabbalah (Bible texts later than the Pentateuch), many interpret his words as meaning that it is a Torah law, though some regard it as a rabbinic prohibition.Rabbi Yehoshua Pfeffer: Shoftim: Halachos of Seclusion (1) Torah & Horaah, Re'eh 5771 (2011).Rabbi Howard Jachter: Yichud - Part Two Rabbi Jachter's Halacha Files Vol.12 No. 7. 18 Kislev 5763/November 23, 2002.

Rashi maintained that insofar as the prohibition of yichud is mandated by the Torah, it is an essential prohibition, whereas rabbinical extensions of the prohibition are enacted as a fence meant to distance a person from forbidden relationships. Hence, leniencies would apply only to the rabbinic additions to the laws of yichud. Halachic consensus, following Maimonides, is, though, that leniencies apply even to Torah-mandated yichud laws.

Laws

The laws of yichud provide for strong restrictions on unrelated members of the opposite sex being secluded together, and milder ones for close family members. Different opinions exist regarding application of these laws both in terms of situation and in terms of the individuals involved. Prohibition of yichud applies to men over 13 years and, generally, girls over three, and a woman over twelve may not be alone with a boy over nine.Rabbi Doniel Neustadt: Hilchos Yichud: Rulings of Harav M. Feinstein Weekly Halacha (1997) torah.org. Even seclusion of short duration is forbidden, if it could potentially last longer.Rabbi N. D. Dubov: Yichud—What, Where And With Whom The Laws of Yichud: Permissibility and Prohibition Regarding the Seclusion of a Man and Woman. Chapter 1. New York 2006, Sichos in English.

Leniencies

There are a number of circumstances under which the prohibition of yichud may be circumvented. Typically, these apply fully to yichud with an observant Jew. Meeting a non-Jew or a secular Jew may require more scrupulousness.

Baaloh B'ir – in town

If the husband is in town (Baaloh B'ir, or Baala Bair) or, more precisely, if it is possible that he can appear suddenly, a woman may be secluded with another man in her home. The fear of his sudden appearance is considered a deterrent to engaging in illicit behavior. If the husband works fixed hours, or if they meet where they are not likely to be found, the husband's presence in town does not circumvent yichud. A close, long-standing relationship (Libo Gas Boh) between the wife and another man also proscribes yichud in spite of the husband's presence in town. The lenience caused by the man's presence in town does not, however, apply to his being secluded with another woman when his wife may appear suddenly. Paradoxically, if a husband gives his wife permission to be secluded with a man, the lenience no longer applies, since she does not fear his sudden entrance.

Rashi believes that the husband's presence in town only mitigates the prohibition rather than abrogating it. The Shulchan Aruch, following Tosafot, however, rule that when the husband is in town, the yichud restriction does not apply at all.

Maimonides and Shulchan Aruch write that the rationale for Baaloh B'ir is that "her husband's fear is upon her." This does not imply a concrete fear that her husband will enter unexpectedly, but rather that she feels a natural inhibition in the knowledge that her husband is close by. As a consequence of this, she can be in yichud with another man in a large city, like London or New York, where the chance that he suddenly appears is non-existent. Neither does her husband's permission undermine the leniency, according to this interpretation. Rashi interprets Baalo B'ir as referring to a concrete fear of sudden exposure. So does rabbi Moshe Feinstein, who consequently rules in a stricter way. Another issue of debate is whether cities that have grown together to form a continuous area are to be treated as one city. Rabbi Shlomo Zalman Auerbach argues that if the wife is in Ramat Gan and the husband is in Tel Aviv, he is still considered to be "in town". Since there are no significant uninhabited areas separating these cities, they are defined as one city from a Halachic perspective.

Pesach Posuach – open door

Yichud is alleviated when the door is open. This principle is known as pesach pasuach lireshus harabim (lit. an open doorway to the public domain). The Shulchan Aruch rules: "If the door is open to the public domain, there is no concern of yichud."Yehoshua Pfeffer: Shoftim: Halachos of Seclusion (2) Torah & Horaah, Shofetim 5771 (2011). This ruling has been interpreted and enlarged in various ways: 1. the door is actually openPitchei Teshuva 22:8 quoting the Beit Meir and rabbi Akiva Eiger (responsa 100) 2. when the door is closed but unlocked 3. then door is locked, but somebody with a key is liable to come in at any time 4. the door is locked, but there is a reasonable possibility that people may knock on the door and expect to be answered (according to Moshe Feinstein). A woman being secluded with another man is also justified when people outside can see through the window what is going on inside the house. In case of a close, long-standing friendship between the man and the woman, however, a more stringent behavior is expected. The leniency usually does not apply late at night, as there is little or no chance that people would come in unexpectedly then.

Shomrim – guards Yichud can be circumvented by the presence of other individuals (shomrim, guards or chaperones), who would serve to provide a check on the man's behavior. Generally, Torah-observant Jewish men qualify as shomrim. Female relatives that permit yichud are: a man's mother; his daughter or granddaughter; his sister; his grandmother; and a woman's mother-in-law, daughter-in-law and sister-in-law. Children aged 6–9 also qualify.

Although yichud with a woman and two or more men, according to most poskim, is permitted during day time and in the evening, the presence of at least three men is required during nighttime sleeping hours. The same goes for situations when children are present instead of adults. Sephardic Jews require the presence of the wife of one of the men for a woman to be secluded with them.

Shulchan Aruch, though, follows Maimonides in ruling that yichud with one woman is prohibited even with many men. The disagreement is based on a passage in Gemara, which states that the permission for two men to be secluded with one woman applies only to kosher people, and tells a story where two amoraim met a woman in a secluded place, and one of them preferred to leave, since perchance only tzaddikim are defined as kosher. Nissim of Gerona considered this an excessive stringency and thought that regular people are defined as kosher. Moses Isserles follows this view and states that yichud with one woman and several men is prohibited only for promiscuous people.Rav Ofer Livnat: Hemdat HaDaf Hayomi: The Prohibition of Yichud eretzhemdah.org, 3 Tishrei 5771/September 11, 2010.

According to Rashi, yichud is permitted when at least three women are present, but most poskim follow Maimonides, who ruled that no number of women present circumvents the prohibition of yichud. Many poskim permit yichud in the presence of the man's grandmother, mother, daughter, granddaughter or sister (over seven years), but do not accept the woman's daughter, granddaughter or sister. Avraham Danzig writes that the prohibition for one man to be in seclusion with two women is only rabbinic, whereas Torah law only prohibits a man from being secluded with one woman.

There are numerous other exceptions; this article presents the haredi point of view.

Siblings

It is preferable that a brother and sister who have reached the age of six should not sleep in the same room.Rabbi N. D. Dubov: Being Careful About Yichud The Laws of Yichud: Permissibility and Prohibition Regarding the Seclusion of a Man and Woman. Chapter 11. New York 2006, Sichos in English. Yichud between a brother and a sister above the age of Bar and Bat Mitzvah is considered appropriate for a short term, but not when their parents are away for an extended period of time. There are various opinions about the duration of a permitted yichud. Some poskim allow only up to three nights; others allow up to thirty days. If the brother and sister live separately and one comes to visit the other, yichud is permitted as long as they do not stay longer than the normal stay of a house guest (where circumstances like the distance of their residence is taken into account). However, when a sibling moves in on a permanent basis, yichud is forbidden even for one day.

Biological children

Yichud with biological children is fully permitted. The Gemara explains that God was moved by the prayers of the Great Assembly to curtail the yetzer hara for incest so there is no need for a prohibition when it comes to biological parents and children.

Adopted children