Mishneh Torah, Marriage 10

Sugya Map

• Issue: The legal status of erusin (betrothal) versus nisu'in (consummation/marriage). Specifically, does erusin + cohabitation = nisu'in, or is chuppah (sequestration/entry to the groom's domain) a distinct, necessary formal act?
• Nafka Mina: Whether a woman is fully "married" for all legal consequences (e.g., inheritance, ketubah obligations, sotah status) prior to the formal chuppah.
• Primary Sources: Mishneh Torah, Marriage 10:1-2; Ketubot 48b; Sotah 24b.

Text Snapshot

Rambam states: "Even when [the husband] consecrated [his arusah] by having sexual relations with her, he is forbidden to engage in sexual relations with her again until he brings her to his home, enters into privacy with her, and thus singles her out as his [wife]" (Mishneh Torah, Marriage 10:2).

• Nuance: The phrase "singles her out" (yichud) is the defining chuppah. Rambam insists that the initial act of cohabitation does not automatically effect nisu'in if the formal sequestration in the groom’s domain is absent.

Readings

• Rambam: Chuppah is a functional act of yichud (sequestration). Erusin is a legal state; nisu'in is a social/spatial transfer.
• Rabbenu Asher (Rosh): Disagrees with Rambam regarding the niddah status. If the couple performs chuppah while the woman is niddah, the nisu'in is binding, whereas Rambam argues the bond remains incomplete because the chuppah was not "fit" for relations (Mishneh Torah, Marriage 10:3).

Friction

• Kushya: If erusin constitutes a binding marriage (she is called "wife"), why is the first sexual act not sufficient to complete the transition to nisu'in?
• Terutz: Rambam maintains a distinction between kiddushin (the bond) and nisu'in (the establishment of the household). The chuppah isn't just an act of intimacy; it is the public transition of the woman into the husband's "domain" (reshut). Intimacy in the father’s house is a transgression because it mimics the husband's domain without the formal transition.

Psak/Practice

The Shulchan Aruch (Even HaEzer 55:1) follows Rambam’s definition of chuppah as yichud. Practically, this necessitates the cheder yichud (private room) following the public ceremony under the canopy. Even if the ceremony is performed, the marriage is not technically consummated under Jewish law without this private sequestration.

Takeaway

Nisu'in is not merely an emotional or ritual bond; it is the formal transfer of the woman into the groom's domain. Without yichud, the legal structure of marriage remains suspended, regardless of whether the couple has already engaged in relations.