DAAT · LEVEL 3 — MASTER SYNTHESIS
Siman 314
סימן שי"ד · דְּבָרִים הָאֲסוּרִים מִשּׁוּם בִּנְיָן וּסְתִירָה
Summary & mnemonics for review
📑 Plan of the synthesis
1. The central axiom
Siman 314 in one sentence.
אין בנין וסתירה בכלים — "no building/demolishing on k'lim." Opening a movable receptacle is in principle not a melachah — except for two exceptions: (1) binyan gamur (structural assembly, or k'li of 40 se'ah = "ohel"); (2) metaken mana (creating a useful opening = makeh be-patish). Hence the modern rule: opening a package to eat is muttar; fashioning a k'li is not.
אין בנין וסתירה בכלים — "no building/demolishing on k'lim." Opening a movable receptacle is in principle not a melachah — except for two exceptions: (1) binyan gamur (structural assembly, or k'li of 40 se'ah = "ohel"); (2) metaken mana (creating a useful opening = makeh be-patish). Hence the modern rule: opening a package to eat is muttar; fashioning a k'li is not.
2. Key concepts condensed
| Concept | Definition | Application |
|---|---|---|
| אין בנין בכלים | No boneh/soser on movable objects | Baseline |
| בנין גמור | Actual building | Exception 1 — assur even on a k'li |
| מתקן מנא | Perfecting / fashioning a k'li | Exception 2 — makeh be-patish |
| דרך אכילה | Opening "to eat" | Muttar — want the content, not the container |
| מ' סאה | 40 se'ah | Beyond, the k'li = "ohel," subject to boneh |
3. Hierarchy of cases
1. Open a package to eat the content → muttar (derech achilah).
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2. Break a glued barrel to take the content, without aiming at a fine hole → muttar.
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3. Break an intact barrel / make a clean hole → assur (soser / makeh be-patish).
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4. Open a can of preserves (= "create" the receptacle) → assur.
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5. Assemble / disassemble a k'li of 40 se'ah or more → assur (binyan gamur).
4. Decision tree
Q1: K'li (movable) or built?
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Q2: Is the object 40 se'ah or more (= ohel)? → boneh/soser apply.
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Q3: Does the act create a useful opening / reusable container? → makeh be-patish, assur.
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Otherwise, opening to eat (derech achilah) → muttar.
5. The can of preserves — fashion or open a k'li?
The siman states אין בנין וסתירה בכלים — no building/demolishing on k'lim. One might conclude that any movable receptacle opens freely on Shabbos. The can of preserves is the test case that shows why that inference is wrong.
Why the can differs from a bag
Tearing a bag of food to eat its content is muttar: it is דרך אכילה, one wants the content. But a can of preserves, once opened, becomes a reusable receptacle — one can store, serve, reuse. Opening it is not "accessing the content": it is completing the fashioning of a k'li.
Edge case: the exception confirms the rule
The whole siman rests on two exceptions. The can belongs to the second — מתקן מנא, perfecting a k'li, a form of makeh be-patish:
Before opening: a sealed block of metal, not yet a usable receptacle.
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The opening act: creates the opening that makes the object fit for its function — the "last hammer blow."
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After: a finished k'li. The melachah of metaken mana has been accomplished.
The decisive criterion is the intent to produce a clean and durable opening. Tearing packaging crudely, without aiming at a clean reusable opening, does not fashion a k'li.
The reasoning to remember: the question is never "is this a movable object?" but "does my act bring forth a k'li or merely give me access to food?". Hence: open cans of preserves before Shabbos.
6. Mnemonic "כב"ד"
כ — K'li (כלי) — no boneh/soser on movable objects.
ב — Binyan gamur (בנין גמור) — exception: structural assembly / 40 se'ah.
ד — Derech achilah (דרך אכילה) — opening to eat = muttar.
— Plus a 4th hidden marker: metaken mana (creating an opening = assur).
7. Pitfalls
Pitfall 1 — The can of preserves: opening on Shabbos = "creating" the receptacle (makeh be-patish). Open before Shabbos.
Pitfall 2 — Aiming at a clean opening: tearing a package is muttar, but do not seek a clean, reusable opening — that would fashion a k'li.
Pitfall 3 — Piercing a barrel / cask: a new hole = assur. Use an existing bung = muttar.
Pitfall 4 — Knife stuck in a barrel: remove on Shabbos only if removed once before Shabbos — else it is a pesik reisha of piercing.
Pitfall 5 — Thinking any movable object is free: a k'li of 40 se'ah and up has the status of ohel — boneh/soser apply.
8. Modern practical cases
| Situation | Conduct |
|---|---|
| Open a food package / bag | Muttar (derech achilah) |
| Open a can of preserves | Assur — open before Shabbos |
| Open a capped bottle | Muttar per most poskim |
| Tamper-band bottle (first opening) | Disputed — consult Rav per minhag |
| Remove cellophane from a bottle | Muttar |
| Open a milk carton / juice box | Muttar |
| Pierce a barrel / cask to serve | Assur (new hole) |
| Banded jam box | Via a non-Jew, or open before Shabbos |
9. Final summary table
| Item | Detail |
|---|---|
| Topic | Boneh/soser applied to receptacles — opening and closing |
| Number of se'ifim | 12 |
| Mishnah Berurah | 53 entries |
| Talmudic sources | Shabbos 146a (chavit she-nishberah); Beitzah 33b |
| Mother principle | אין בנין וסתירה בכלים — with 2 exceptions |
| Modern issue | Can of preserves = open before Shabbos |
| Practical ruling | Open a package to eat = muttar; fashion a receptacle = assur |
10. Practical mandates of Siman 314
Opening receptacles on Shabbos — checklist
- Before Shabbos: open cans of preserves and any problematic container.
- Food packages: open/tear to eat = muttar (derech achilah).
- Do not aim at a clean and reusable opening (= fashioning a k'li).
- Do not pierce a new hole in a barrel.
- K'li of 40 se'ah and up = ohel: boneh/soser apply.
- Tightly banded packaging: via a non-Jew if necessary.
- In doubt → consult the Rav.
📚 Recap of the study path
At 3 levels:
At 3 levels:
- 🌱 Level 1 — Foundation
- ⚡ Level 2 — Lamdan
- ✨ Level 3 — Synthesis
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DAAT · Rav Yossef Haim Samama
Siman 314 · Level 3 — Master Synthesis
DAAT · Rav Yossef Haim Samama
Siman 314 · Level 3 — Master Synthesis