B”H, 1) When preparing for Shabbos on Yom Tov, we should do our best to follow the opinion of Rabah who bases the permit to prepare on the concept of ‘ho-il’ (see previous lesson). Practically, this means not to make our Shabbos preparations too late in the day on Friday (Yom Tov). If necessary, we may rely on the opinion of Rav Chisda and continue our preparations as late as sunset, at the very latest (especially if Friday is the second day of Yom Tov). (Ed. Remember - Shabbos candle-lighting comes 18 minutes before sunset anyway.)
2 ) We follow the opinion of Beis Hillel who rules that essentially only one food is needed for the Eruv Tavshilin (henceforth to be abbreviated ‘ET’). However, halacha prefers that we use one food for each medium – cooking and baking! That is why the custom is to take one cooked item and one baked item. (See more below.) If only a cooked item was used for the ET, one may still bake (and of course cook). If only a baked dish was used, it is questionable whether one may cook. (Ed. A shaila should be asked.)
3) It is a ‘Hidur mitzvah’ (beautification of the mitzvah) to use a whole loaf (or matzah) for the baked item and meat or fish for the cooked item. The Mishnah Berura mentions the custom of using an egg, which is commonly used by people. Whatever the cooked item is, it must be something that one would eat with bread, as opposed to, say, porridge, which is a starch and not typically eaten with bread. The cooked item should preferably be a ‘k’beitza’ (egg-sized), but at least a ‘kezayis’ (olive-sized).
4) It is a nice practice to use the ET bread as ‘lechem mishnah’ (one of the two loaves) at the Shabbos meals and to finally eat it at the ‘seuda shlishis’ (the third meal on Shabbos), along with the cooked item. If one did not eat them at all, the ET would not be invalidated. However, the idea is that once a mitzvah is done with an object, it should be used again for another, and another!
5) What is considered “cooked” for the cooked item? It could be roasted, stewed, boiled, preserved (which is halachically considered in many ways as a form of cooking), or smoked. Even if the food is perfectly edible without cooking – e.g. fruit, salted fish – it may still be used for the ET in its cooked form.
6) One may use a cooked or baked item, even though it was not prepared initially to be used as an ET. If absolutely necessary, one could even use food that was leftover in a pot (e.g. legumes stuck to the bottom), as long as it was at least the size of a ‘kezayis’.