THE MAXIMUM HEIGHT OF A KORAH (Yerushalmi Perek 1 Halachah 1 Daf 5a)

מבוי שנפרץ מצידו כלפי ראשו רבנן דקיסרין א"ר חייה ר' יוסה אם יש שם עומד ארבעה צריך קורה ואי לא לא צריך


If a Mavuy was breached on its side near the opening - Rabanan of Kisarin citing R. Chiya citing R. Yosah said, if four Tefachim remain [until the Korah at the opening], an [additional] Korah is needed to permit the breach. If not, it is not needed.

מה בינו למבוי שיש לו שני פתחים אילו מבוי שיש לו שני פתחים שמא אינו נותן קורה על אחד מהן ומתיר


Question: What is the difference between this and a Mavuy with two openings? A Mavuy with two openings, does he not put a Korah on one of them, and [this suffices to] permit it [like a Beraisa above (3b) says]?!

אמר רב נחמן בר יעקב ומבוי שיש לו שני פתחים אין דרך בני אדם ליכנס בפתח הזה ולצאת בזה ברם הכא דרך בני אדם ליכנס בפתח זה ולצאת בפירצה


Answer (Rav Nachman bar Yitzchak): A Mavuy with two openings, people do not enter through one opening and leave through this (the other, since both open to the same Reshus ha'Rabim). However, here, people enter through the opening and leave through the breach.

קורה אחת מהו שתתיר שני מבואות


Question: Can one Korah permit two Mavo'os [side by side that share a common wall? The Korah is over the openings of both, and rests on the outer wall, but not on the common wall, which is lower.]

ר' ירמיה אמר רבי זירא ורבי אבהו חד אמר אסור וחד אמר מותר


Answer: R. Yirmeyah citing R. Zeira, and R. Avahu, argued about this. One forbade, and one permitted.

מאן דמר אסור בניתנין למעלה מג' לכותלי המבוי מאן דמר מותר בניתנין למטה מג' בכותלי המבוי


(They do not argue.) The one who forbade, this is when it is three above the [middle] walls. The one who permitted, this is when it is less than three above the [middle] walls (it is as if it rests on it, due to Lavud. MEICHAL HA'MAYIM asks that the same applies to a single Mavuy! He answers that for a single Mavuy, normally they insert the Korah into the wall. Here it is not possible, due to the wall in the middle. Rather, it must rest on pegs jutting out from the wall. One might have thought that we decree even when it is within three due to when it is above three.)


Note: Seemingly, it should say three above or below the middle wall (singular). Perhaps we discuss when it is not a common wall, rather, the left wall of the right Mavuy is next to the right wall of the left Mavuy.