Arukh HaShulchan, Orach Chaim 307:33-308:6

Sugya Map

• Issue: The parameters of Kishra (tying) and Matir (untying) on Shabbat, specifically regarding permanent vs. temporary knots (Kesher shel kayama vs. Kesher hedyot).
• Primary Sources: Mishnah Shabbat 111b–112a; Shulchan Aruch OC 317; Arukh HaShulchan (AHS) 307:33–308:6.
• Nafka Mina: Whether a knot tied for a single day’s use—but intended to remain for that duration—is considered "permanent" (shel kayama) or "temporary" (he'ui l'prakim). The scope of Tashmish (utility) vs. Uman (artistry).

Text Snapshot

Arukh HaShulchan 307:33: "וכל קשר שאינו של קיימא, אלא שעושין אותו לזמן... מותר לקושרו." Arukh HaShulchan 308:1: "ודע, דעיקר התלוי בקשרים הוא אם הוא של קיימא או אינו של קיימא."

Leshon Nuance: Note R' Epstein’s deliberate choice of "לזמן" (for a time) as the inverse of "קיימא" (enduring). While the Gemara (Shabbat 112a) focuses on the ma'aseh (the craftsmanship of the knot), AHS shifts the weight toward the kavanah (intent) and zman (temporal duration). The distinction between "temporary" and "permanent" is not merely physical durability but functional longevity.

Readings

The Rishonim: Rambam vs. Rashi

Rambam (Hilchot Shabbat 10:1) posits that the issur revolves around the Uman (craftsman) aspect. If a person ties a knot that a craftsman would create, they are chayav. Rashi (Shabbat 112a s.v. Kesher shel kayama), conversely, emphasizes the durability of the knot. For Rashi, kayama is a functional category: if it is destined to stay, it is a knot of "existence."

Arukh HaShulchan’s Chiddush

R' Epstein, in 307:33, synthesizes these by suggesting that kayama is defined by the da'at of the owner. His brilliance lies in the assertion that if one ties a knot for a specific period—even if that period is long—it is he'ui l'prakim (temporary). He argues that the definition of kayama is not a specific number of days (e.g., a week or a month), but rather whether the knot is intended to remain indefinitely. If the user intends to untie it, even a "strong" knot is permitted.

The Acharonim: Mishna Berura vs. AHS

The Mishna Berura (317:5) is notoriously stringent, adopting the Taz’s position that even a knot meant for a day is prohibited if it is "tight." AHS, however, is more lenient, focusing on the nature of the knot. He posits that if it is not a kesher uman (artisan knot) and it is destined to be untied, it lacks the melechet machshevet required for the melacha of Ko'sher.

Friction: The Knot of Contention

The Strongest Kushya

If Kesher shel kayama is defined by the intent to eventually untie it, how do we reconcile this with the Gemara in Shabbat 112a, which explicitly states that a knot meant for a day is prohibited? The Taz (317:1) argues that the Gemara establishes a temporal threshold. If it is meant to stay for a duration, it is kayama. AHS’s insistence that "intent to untie" renders it temporary seems to contradict the very definition of kayama as "enduring."

The Terutz (Two-Fold)

1. Functional Intent: AHS would argue that the Gemara refers to a knot that is capable of lasting indefinitely. If I tie my shoelaces, they are intended to last until I take them off at night. Is this kayama? AHS distinguishes between a knot that requires untying (by force or cutting) versus a knot designed to be untied easily. If a knot is not "professional," the kavanah to untie it that same day removes the melacha status entirely.
2. The "Uman" Filter: AHS implicitly argues that the Gemara’s prohibition applies to knots that mimic the "expert" construction. If a person ties a simple bow (which is he'ui l'prakim), even if they leave it for a week, it is not kayama. The issur is not the time, but the type.

Intertext

• Mishna Shabbat 11:5: "הקושר קשר של קיימא... חייב." The Mishna provides the category, but not the duration. This ambiguity is exactly what AHS exploits to prioritize the nature of the knot over the time element.
• Shulchan Aruch OC 317:1: The SA states that one who ties a kesher hedyot (layman's knot) is exempt. AHS (308:2) uses this to define the "floor" of the prohibition—if it’s not uman, it’s not melacha.

Psak/Practice

In practical application, AHS serves as a l'kula (lenient) anchor. While Mishna Berura pushes for extreme caution regarding any semi-permanent knot, AHS provides the logic for why everyday knots (like tying a garbage bag or a simple string) are permissible: they are not uman level, and they are not intended to be permanent fixtures of the object. AHS effectively shifts the focus from the physics of the knot to the teleology of the knot.

Takeaway

Kesher is not about how long a knot lasts, but about whether the knot is a "construct" of permanence or merely a temporary tool. If you intend to untie it, the knot is a servant, not a structure.