Arukh HaShulchan, Orach Chaim 277:9-279:1

Sugya Map

• The Issue: The tension between the shiur of kiddush (the requisite volume of wine) and the shiur of b’rachah (the consumption required to trigger a bracha achrona). Specifically, does the kiddush obligation terminate at the meliah lugmav (cheek-full) threshold, or does it require a revi’it (quarter-log) for the mitzvah to be complete?
• Nafka Mina:
  • Can one rely on kiddush with a cup that lacks a full revi’it if the meliah lugmav is present?
  • Does kiddush fundamentally function as a birkat hamitzvah (requiring the shiur of the mitzvah) or a birkat hanehenin (requiring the shiur of consumption)?
• Primary Sources:
  • Pesachim 107a (The debate over meliah lugmav).
  • Shulchan Aruch, Orach Chaim 271:10-14.
  • Arukh HaShulchan, Orach Chaim 277:9–279:1.

Text Snapshot

"והנה שיעור כוס של קידוש הוא רביעית... ואם אין בכוס רביעית אלא מלא לוגמיו דהיינו שיכול לשתות בבת אחת, ויש דעות בזה, ועיקר כדברי הרא"ש שצריך רביעית" (ערוך השולחן, אורח חיים 277:9).

• Leshon Nuance: The Arukh HaShulchan (AHS) employs the term "עיקר" (the main/essential view) as a halachic anchor. Note the shift from the Rema’s leniency regarding meliah lugmav to the AHS’s insistence on revi’it. The dikduk here is subtle: he frames the meliah lugmav not as an independent shiur of kiddush, but as a fallback position for bedieved (post-facto) scenarios, yet asserts the lechatchila status of revi’it with authoritative finality.

Readings

The Rishonim: Rashi vs. The Rosh

The sugya pivots on the interpretation of Pesachim 107a. Rashi (s.v. meliah lugmav) defines the shiur as the amount a person can hold in their mouth while the cheeks are distended. The Rosh (Pesachim 10:14), however, posits that kiddush is fundamentally a kiddush of the day, which requires the dignity of a revi’it—the standard measure for kos shel beracha.

The chiddush of the Rosh is that kiddush is not merely a drink; it is an act of kiddush. If the cup is deficient, the kiddush is functionally incomplete, even if the liquid satisfies the biological requirement of meliah lugmav.

The Acharonim: Arukh HaShulchan’s Synthesis

The AHS, in 277:9, executes a classic "Arukh HaShulchan" maneuver: he acknowledges the machloket, cites the Beit Yosef, but ultimately grounds the psak in the Rosh. His chiddush lies in the harmonization of halacha with minhag. He writes:

"דאף על גב דקיימא לן כרבנן דשיעורא מלא לוגמיו... מכל מקום לכתחילה ודאי צריך רביעית."

He distinguishes between the din (what is technically sufficient) and the hiddur (the integrity of the mitzvah). He views the revi’it not as a mere quantitative requirement, but as a qualitative necessity for kiddush. He effectively sidelines the meliah lugmav for lechatchila purposes, shielding the practitioner from the uncertainty of varying face/cheek shapes.

Friction

The Kushya: The Deflation of the Shiur

The inherent friction: If chazal established meliah lugmav as the shiur for drinking arba kosot (according to many), why does the AHS insist on revi’it for kiddush? If the mitzvah is to "sanctify the day," and the chachamim define the shiur of a "cup" as meliah lugmav, then revi’it is an ad hoc addition that lacks source-text rigidity.

Furthermore, if one drinks meliah lugmav, they have technically fulfilled the drinking requirement. Why should the deficiency of the cup’s capacity invalidate the kiddush?

The Terutz

The AHS responds implicitly through his treatment of 277:11. He argues that kiddush requires a "cup of blessing." A cup that holds less than a revi’it is arguably not a "cup" in the context of birkat hamitzvah. The shiur of kiddush is tethered to the shiur of the kos, which is inherently revi’it.

His deeper terutz is structural: Kiddush is an act of kiddush, not merely a consumption of wine. By requiring a revi’it, the chachamim ensure that the vessel is substantial enough to represent the day. A tiny sip, even if it fills the cheeks, fails the kavod (dignity) of the mitzvah. The terutz is therefore qualitative: revi’it is the shiur of the object; meliah lugmav is merely the shiur of the act.

Intertext

Parallel: The Nature of "Kos"

Compare this to SA Orach Chaim 183, regarding the kos for Birkat Hamazon. The Mishnah Berurah (183:2) mirrors the AHS here, requiring a full revi’it for the kos to be valid. The parallel is clear: when Chazal speak of a kos in the context of a mitzvah, they imply a specific volume that transcends the biological meliah lugmav.

Responsa Context

See Igrot Moshe (OC 2:75), where R. Moshe Feinstein grapples with the measurement of revi’it in modern vessels. He aligns with the AHS’s conservative approach, arguing that when in doubt regarding a shiur of chazal, one must err on the side of the larger volume to ensure the mitzvah is performed correctly. This confirms the AHS’s heuristic: lechatchila always demands the revi’it.

Psak/Practice

In practical application, the AHS sets a high bar for hiddur. While bedieved (e.g., if one only has a small cup), one might rely on meliah lugmav (assuming the person has a significant cheek capacity), the psak for the observant Jew is to ensure the cup holds at least 3.0–3.3 fluid ounces (or more, depending on your revi’it calculation, e.g., Rav Chaim Naeh vs. Chazon Ish).

Meta-Psak Heuristic: When the poskim provide a shiur as a "minimum," treat it as a floor, not a ceiling. Use a cup that holds at least a revi’it and a half, ensuring the revi’it is consumed definitively. Never rely on the meliah lugmav leniency unless in an environment of sha’at hadchak (duress).

Takeaway

The Arukh HaShulchan reminds us that mitzvot are not merely algorithmic; they possess a qualitative dimension where the vessel itself (the kos) must reflect the significance of the act. Meliah lugmav is a biological limit; revi’it is a halachic standard.