מראה מקומות

Rabbi Yitzchok Gutterman

The גמרא mentions that there are opinions who hold לית ליה מוקצה. It is important to understand what this means. There is no opinion who does not hold of מוקצה at all. See the ש"י ד"ה ומ"ש בית יוסף או"ח סימן who says that when we say that ר"ש is לית ליה מוקצה, for example, we mean to say that he doesn’t hold of מיגו דאתקצאי לבין השמשות אתקצאי לכולי יומא היכא דלא דחיא בידים. In other words, it is only relevant to cases where something was מוקצה before שבת and would no longer be מוקצה now if not for the fact that it had been מוקצה when שבת Even in those cases, there are times when ר"ש would agree where you were דחיא בידים which we will learn about in the coming דפים. In the vast majority of classes of מוקצה, he would agree that it is אסור בטלטול.
The גמרא says that if the chicken had been set aside for shechting it, then the egg that it laid would be permitted because it is אוכלא דאיפרת. There is a very fundamental question here that the ראשונים deal with: רש"י explained the concept of נולד as being מוקצה from use since you can’t have דעת on something that is not in the world. Therefore, since the egg was not in the world before יו"ט, it is inherently נולד. If that is the case, why should the egg be permitted just because it’s mother was intended for shechting? The fact is that the egg was not in the world so how could you have had דעת for it? רש"י and the ר"ן seem to understand that since the egg was food which came from food, it is not really new—it’s just an extension of the chicken which was already considered food. See תוספות רבינו פּרץ who disagrees and says that the reason it is permitted is because the egg itself actually existed in the mother yesterday. As such, since you could have eaten the chicken with the egg inside it yesterday, the egg was really an egg even yesterday. See רעק"א דף לז: who points out that the נפקא מינה between these two opinions should be the case of milking a cow on יו"ט. If you hold like רש"י, then if the milk came from a cow that was meant for schechting, the milk would not be נולד since it came from food. However, if you hold like תוספות רבינו פּרץ, then the milk should always be considered נולד since the milk did not exist in any way the day before (this would be a question on תוספות רבינו פּרץ since there is a case where the גמרא says that the milk is permitted).
The ראשונים ask a question that is the inverse of the question mentioned in number two above. They ask why it is forbidden to eat the eggs of a chicken that that is meant to lay eggs and not to schecht. How could you say that you did not have דעת for the eggs? That’s what you have the chicken around for?! See the first בעל המאור in the מסכתא who says that אה"נ, the egg would have been permitted if it was meant to produce edible eggs. However, our גמרא means that the chicken was meant to lay eggs that hatch! Therefore, other eggs it lays are נולד. See the ראב"ד there that disagrees and says that the eggs are always forbidden since they come from a מוקצה item, and you can’t separate the egg from the status of the mother. A נפקא מינה is the case of milking the cow. According to the בעל המאור, it should be permitted if the cow was meant for milking, even on שבת. According to the ראב"ד, it would be forbidden on שבת since you cannot shecht it on שבת.
See תוספות ד"ה והיה who brings a מחלוקת מדרשים as to whether מן fell on יו"ט or not. Assuming it did not, it should come out that when יו"ט falls out the day before שבת that three pieces of מן fell on ערב יו"ט. See the נודע ביהודה brought in the בנין שלמה סימן י"ח who wonders why we don’t need three rolls for לחם משנה when יו"ט falls out the day before שבת.

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Rabbi Schachne Weinberger

מס' ביצה דף ב ע''א

- שאור בכזית, צל''ח

- תד''ה ביצה, מרומי שדה (נצי''ב) ד''ה במשנה

- תד''ה ובית הלל, תירוץ א' ביאור הלכה ס' רע''ט סעיף א' - תירוץ ב', רש''ש - תירוץ ג', מ''ב ס' ש''ט סקי''ח

דף ב ע''ב

- תד''ה שאין מבקעין, רע''א - מג''א ש''ח ס''ק י''ט

- כח דהתירא עדיף, רע''א, צל''ח

- מחלוקת ר''ש ור''י במוקצה, קהלות יעקב ס' ד'

- הכנה דרבה, אפיקי ים ח''ב ס' י''ז

- תד''ה והי', קהלות יעקב ס' א'

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See daf summary by Rabbi Chaim Smulovitz in the PDF below.

Rosh Hashana 5a