Intro: Anyone who has ever dabbled in Mishna – particularly the Tractate called ‘Beitzah’ (lit. “egg”) which covers the Oral Laws concerning Yom Tov – is familiar with the opening case: “An egg that was laid on Yom Tov - Beis Shamai say: It may be eaten. But Beis Hillel say: It may not be eaten!”! The current siman lays out (n.p.i. – promise!) the halachos that pertain to this case, and related ones. For this lesson, we will present the basic case and the halachic theory behind it. Chances are that you will not need to apply these halachos often, but it sure would be nice to understand this famous Mishna, wouldn’t it? (Credits to the Artscroll Mishnah Series: Maseches Beitzah, pp. 10-11)
Mishnah Beitzah (1:1): “An egg that was laid on Yom Tov, Beis Shamai say: It may be eaten. But Beis Hillel say: It may not be eaten.”
Quoted mostly from the Yad Avraham Commentary: The Gemara proposes various reasons for Beis Hillel’s prohibition. Rabah (whose explanation is accepted as halacha by most authorities) explains [Gemara Beitzah 2b] that an egg which is laid one day is always fully developed (within the chicken) on the previous day. Thus, if one eats an egg which was laid today, he is eating something which was prepared yesterday. If that day was Shabbos (i.e. the egg was laid on Yom Tov which was on Sunday), and the egg was eaten on Yom Tov, this would result in preparation for Yom Tov having occurred on Shabbos… Rabah expounds the principle of ‘hachana’ (lit. preparation), which forbids the preparation of food (or other articles) on Yom Tov for use on Shabbos, or on Shabbos for use on Yom Tov. Such preparation renders the prepared object prohibited for use on the Shabbos or Yom Tov for which it was prepared, even though no forbidden labor was involved in the preparation (i.e. no human endeavor was involved in the completion of this egg, as it was a natural process conducted inside the chicken’s body!) Rabah derives this principle from Shmos 16:5 which states: “And it shall be on the sixth day and they shall prepare what they bring in.” - meaning that all preparations for Shabbos and Yom Tov should be done on preceding weekdays, not holy days. (We have been brief in our explanation of this source – Ed.) This reasoning would seem to apply only to an egg laid on Yom Tov immediately preceding or following Shabbos; an egg laid on a Yom Tov not bordering on Shabbos should be permissible, by this logic. However, the Sages prohibited such an egg too, for an egg laid on a regular Yom Tov or Shabbos would easily be confused with one laid on a Yom Tov in proximity to a Shabbos. Hence, the halacha according to Beis Hillel is that an egg laid on any Yom Tov (or Shabbos) is prohibited, regardless of when in the week Yom Tov occurs.
Ed. The remainder of this siman deals with details of this case, and related cases, such as a newly-hatched chick or a newborn calf on Yom Tov. The general rules of muktzah on Yom Tov play a role in these cases as well. We have mentioned only the ‘Hachana of Rabah’ principle, because that is the unique one that emerges from this case.