Hiddur Mitzvah vis-à-vis Eiruv tavshilin
There are several ways one can perform the mitzvah of eiruv tavshilin in a more mehudar way:
The cooked food should be cooked on erev Yom Tov for the sake of Shabbos and specifically for the sake of eiruv tavshilin.148
The cooked food should be a significant portion.149
The baked food should be whole, e.g., a whole challah or matzah.150
The challah or matzah should be used for lechem mishneh on Friday night and Shabbos morning,151 and should then be broken and eaten at seudah shelishis.152
The cooked food should also be eaten during one of the Shabbos meals.153
When the First Day of Yom Tov is on Thursday
When the first day of Yom Tov is on Thursday, one may not cook for Shabbos on Thursday.154 One may, however, cook for Shabbos on Thursday night, which is already the second day of Yom Tov.
The Halachos of Eiruv Tavshilin for Guests
Only one eiruv tavshilin is required for the entire household. The eiruv will cover everyone who resides in the house, including married children and guests who are spending the Yom Tov as part of that household.155 However, some Poskim recommend that guests make their own eiruv tavshilin without a berachah (or include themselves in the eiruv of the household-head by acquiring a share in it).156
If the host is not setting an eiruv tavshilin, the guest must set one for himself. An example of this would be a ben chutz la’aretz visiting Eretz Yisrael, and who is a guest in the home of a ben Eretz Yisrael on the second day of Yom Tov (which is also erev Shabbos). Since the host is not observing Yom Tov on that day, he obviously will not be setting an eiruv tavshilin. The guest, who is observing Yom Tov that day, will need to set his own eiruv before Yom Tov.
However, it is common that a guest will not be making any preparations for Shabbos at all, as his host will probably be making them. In that case, the only activity which might require an eiruv tavshilin is lighting the Shabbos candles (see below) – and it is disputed whether or not an eiruv tavshilin is required in order to light Shabbos candles.157 Therefore, some Poskim maintain that the guest should set an eiruv tavshilin but, in this case, not recite a berachah. This holds true for anyone who is certain that he will not be preparing for Shabbos on Yom Tov (see footnote).158
Note that, generally, one has a fallback option of relying on the eiruv of the Rav of the city and the like. However, one should check if this option is available in the scenario of a ben chutz la’aretz in Eretz Yisrael. A Rav in Eretz Yisrael might not have made an eiruv tavshilin,159 since Friday is not Yom Tov for him.
Which Types of Shabbos Preparations Require an Eiruv Tavshilin
An eiruv tavshilin is required not just for cooking and baking but for any melachah being done for Shabbos, e.g., grinding, sorting, insulating, transporting, or lighting candles.160
Some permit Shabbos preparations that do not involve any type of melachah, but merely exertion, even if an eiruv tavshilin was not set.161
Preparations for Shabbos that are Prohibited, Even with an Eiruv Tavshilin
An eiruv allows one to do something which would otherwise be rabbinically prohibited. It does not allow one to do a Biblically prohibited act of melachah. As mentioned above, there are two opinions as to why performing melachah on Yom Tov for Shabbos is not Biblically prohibited. According to one opinion this is because of the principle of ho’il – since the food could theoretically be used on Yom Tov for guests, it is considered as if it was prepared for Yom Tov. However, this is relevant only if the food will be ready while it is still Yom Tov. If one wishes to start cooking for Shabbos very close to the end of Yom Tov, the food will not be ready in time for guests to enjoy it on Yom Tov. The principle of ho’il is not relevant in this instance, and preparing for Shabbos in this way might be Biblically prohibited. Therefore, lechatchilah, any food being prepared on Yom Tov for Shabbos should be cooked early enough in the day that it will be edible on Yom Tov. Bedieved, or under extenuating circumstances, it is permitted to cook on Yom Tov for Shabbos even if the food will not be edible before the end of Yom Tov.162
If No Eiruv Was Made
Someone who forgot to prepare an eiruv tavshilin on erev Yom Tov before sunset (or someone who set an eiruv but it got lost or spoiled) may not cook on Friday for Shabbos.
However, there are still ways that food can be prepared for Shabbos. A qualified rabbinical authority should be consulted, as they involve many details. We list them here, very concisely. One may:
Set an eiruv tavshilin after sunset during bein hashemashos (even with a berachah).163 Once Ma’ariv has been recited, however, an eiruv tavshilin cannot be made, even if it is still before sunset.
Set an eiruv tavshilin while in shul even though he does not have immediate access to cooked food.164 That is, he should think of a specific cooked food and a specific baked food that he has in his house and mentally designate them as the eiruv tavshilin, even though he is not at home. He then recites the appropriate text, cited above, exchanging the words בהדין עירובא (with this eiruv) for בעירובא דאית לי בתוך ביתי (with the eiruv that I have in my home).
When there is a three-day Yom Tov (Thursday and Friday are Yom Tov, with Shabbos immediately following), make an eiruv on the first day of Yom Tov (unless it is Rosh Hashanah). A special text is recited, and the berachah is not recited.165
Rely on the Rav’s eiruv, which is intended to include anyone who forgot or was unable at the last minute to make an eiruv.166 This cannot be relied upon for one who did not make an eiruv out of laziness.167
Cook extra food for Yom Tov so that he will have food left over for Shabbos. This is permitted only if he has not yet eaten the Yom Tov day meal.168
Give his raw ingredients to another person (who did set an eiruv) to cook, and have that person cook for him. The cooking may take place even in the house of the one who failed to make an eiruv.169
148 Beiur Halachah 527:6, ד"ה עדשים, and 14, ד"ה לכתחלה.
149 Mishnah Berurah ibid., note 8.
150 R’ Shmuel Wosner (Koveitz Mibeis Levi I, page 52).
151 This is according to those who do not cut both loaves at each meal. Those who follow the opinion of the Vilna Gaon and cut into two loaves at every meal (see Mishnah Berurah 274, note 4) should simply use the loaf of eiruv tavshilin for lechem mishneh at seudah shlishis (based on Maharil cited in Mishnah Berurah 527, note 11; cf. Shemiras Shabbos Kehilchasah 2, footnote 37).
152 Mishnah Berurah ibid., notes 11 and 48.
153 R’ Shlomo Zalman Auerbach (cited in Shemiras Shabbos Kehilchasah 2, note 37; Shulchan Shlomo 527:13-3, note 15).
154 Chapter 527, Passage 13.
155 Eishel Avraham 527; R’ Yosef Shalom Elyashiv (cited in Mevakshei Torah, Yom Tov, vol. I, page 218).
156 See Haggadah Shel Pesach Moadim Uzemanim, page 39, in footnotes. If someone will be dining at the homes of different hosts over Yom Tov, it appears that he should set his own eiruv tavshilin.
157 Ma’amar Mordechai 527:18; Eiruv Tavshilin Ha’aruch 4, footnote 28, citing Chazon Ish; Minchas Shlomo, Tinyana, 58:3. (Cf. Moriah 371-372, page 226, footnote 1, qualifying R’ Shlomo Zalman Auerbach’s ruling.) Some maintain that even in this case a berachah may be recited (see Moadim Uzemanim, VII:122). Although the guest is not intending to make any food preparations for Shabbos, the eiruv tavshilin is nevertheless valid and allows him to prepare for Shabbos if he wishes to.
158 If there is, however, a chance he may want to prepare for Shabbos on Yom Tov, all opinions would agree that a berachah should be recited (see Chut Shani, page 150).
158Therefore, for example, we can differentiate between someone staying in a hotel for Pesach and someone staying in someone else’s home. Someone staying in a hotel presumably has no way of preparing food for Shabbos at all and, according to this opinion, should not recite a berachah. Someone being hosted in a private home, on the other hand, might well assist with the food preparation for Shabbos, and therefore may recite a berachah upon setting an eiruv (if he sets his own eiruv).
159 See Minchas Shlomo, Tinyana 49:3, that a ben Eretz Yisrael may set an eiruv tavshilin (without a berachah) for a ben chutz la’aretz even though Friday is not Yom Tov for the person setting the eiruv.
160 Shulchan Aruch 527:12, 19; Mishnah Berurah, note 37 ad loc.
161 See Shemiras Shabbos Kehilchasah 2, footnote 41; Shevet HaLevi III:68 and IV:51:2.
162 Mishnah Berurah 527, note 3, and Beiur Halachah to Passage 1 ad loc., ד"ה וע"י עירוב. Cf. Aruch Hashulchan 3 ad loc., who is more lenient and permits this even lechatchilah.
163 Chapter 527, Passage 1.
164 Minchas Yitzchak VII:36; R’ Shlomo Zalman Auerbach (Shulchan Shlomo 527:2); R’ Yosef Shalom Elyashiv (Ashrei Ha’ish, III., page 41). Some Poskim disagree with this ruling, noting that Mishnah Berurah 527, note 4, implies that an eiruv set in this manner is not valid (see She’arim Hametzuyanim Behalachah 102:4).
165 Shulchan Aruch ibid., Passage 22.
166 Ibid., Passage 7. However, one may rely on the Rav’s eiruv only once (Mishnah Berurah ibid., note 22). Cf. Aruch Hashulchan, ibid. 18, who maintains that it may be relied upon even more than once.
167 Sha’ar Hatziyun ibid., note 32.
168 Chapter 527, Passage 21. Therefore, it is permitted to cook many different foods, so long as he will partake of each of them on Yom Tov (Mishnah Berurah, note 71 ad loc.).
169 Ibid., Passage 20.