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The Laws of Eruv Tavshilin – Shavuos 2023

By: Rabbi Akiva Niehaus, cRc Director of Kashrus Operations

This Shavuos, 5783, we will have the privilege of performing the special mitzvah of Eruv Tavshilin on Thursday, prior to the first day of Yom Tov. When Yom Tov falls out on Friday – leading into Shabbos – every household must prepare an Eruv Tavshilin before Yom Tov in preparation for Shabbos. By setting aside some cooked food and baked food in honor of Shabbos before the onset of Yom Tov, one is permitted to prepare Shabbos foods on Friday. Let us explore why it is necessary, how it works, and the procedure used.


The Background

On Yom Tov, like Shabbos, one may not transgress the 39 forbidden melachos, with a few exceptions. One of the exceptions is the melacha of bishul (cooking) as it states (Shemos 12:16), “the only work that may be performed on Yom Tov is that which is needed so that everyone will be able to eat.” However, cooking on Yom Tov is only permitted if the food will be consumed on Yom Tov; cooking for a later date, be it a regular weekday, another day of Yom Tov, or Shabbos, is forbidden, and, according to some opinions, may involve a Biblical prohibition. Accordingly, when Yom Tov occurs on Friday, it should be forbidden to prepare food on Friday for the next day, Shabbos. How, then, is one able to prepare fresh, tasty food for Shabbos?

To alleviate this concern, Chazal instituted a new procedure called Eruv Tavshilin, literally, “the mixture of foods”. If one prepares food for Shabbos before the onset of Yom Tov, he may continue the preparation for Shabbos on Yom Tov. The rationale for this is that if one begins the food preparation before Yom Tov, any cooking on Yom Tov is considered a mere continuation of the original cooking (Rama O.C. 527:1). Initially, one must be careful to ensure that all food prepared on Friday is edible before Shabbos begins. However, in extenuating circumstances, one may prepare food on Friday for Shabbos even if the food will not be edible when Shabbos begins (Mishnah Berurah 527:3). 1 Accordingly, for example, special care must be taken to ensure that the cholent is prepared early enough on Friday to allow it to be edible (at least one-third cooked) by the time Shabbos begins.

As an extension of the above requirement, many people have a custom to accept Shabbos early when Yom Tov falls on Friday to ensure that all food preparation is completed well before nightfall (ibid).


The Procedure

The Eruv should be prepared on Erev Yom Tov, this year, Thursday, May 25th. If the Eruv was prepared on an earlier day, the Eruv is effective but should ideally be prepared again on Erev Yom Tov without a bracha (Shulchan Aruch 527:14).

Because the vast majority of food preparations involve cooking and baking, we set aside a cooked item and a baked item for the Eruv.2 As explained, by setting aside these two items for Shabbos before the onset of Yom Tov, all subsequent preparations are considered a continuation of the original preparation.

The cooked item should be at least the size of a k’zayis (approximately 1 fl. oz.) (Shulchan Aruch 527:3). It should be an item that is usually accompanied by bread in a meal (e.g., meat, fish, or eggs); the common custom is to use a hard-boiled egg.3 Although one may use a cooked food even if it was not cooked specifically for the Eruv, the optimal form of the mitzvah is performed when one cooks a food specifically for the Eruv.4

The baked item should ideally be whole and at least the size of a k’beitza (2 fl. oz.), but it is sufficient if the piece is at least the size of a k’zayis (Rama 527:3). Many people have a custom to use matzah, but if this is unavailable, bread – or even cake or cookies from the five species of grain – may be used (for a Yom Tov other than Pesach).

The baked and cooked items are held in one’s hand, and the bracha, “… al mitzvas eruv,” is recited, followed by the declaration, “Bahadein eiruva…” as printed in many siddurim. The declaration states that, with the Eruv, preparation for Shabbos may take place on Yom Tov. It is important that one understand the meaning of the declaration; if necessary, the declaration may be recited in English.5 After the declaration, the food items should be stored in a safe location so that they remain intact until Shabbos. In fact, the Eruv must stay intact until the preparations for Shabbos have been completed.6 It is customary to use the Eruv’s baked item, if it is a whole bread or matzah, for lechem mishnah on Shabbos, and then to eat the Eruv foods during Seudah Shlishis.7


Forgot to Prepare the Eruv?

If one forgot to prepare the Eruv before the onset of Yom Tov and remembered before tzeis hakochavim (nightfall), he may still prepare the Eruv Tavshilin.8 If he does not remember until after tzeis hakochavim, he may no longer prepare the Eruv and should consult his Rav as to how he should manage meals for Shabbos.9


What Kind of Preparations are Permitted?

The Eruv is primarily designed to allow cooking and baking on Friday for Shabbos. In addition, the Eruv permits activities indirectly related to food preparation (e.g., lighting candles and washing dishes with hot water). It also permits preparations which do not involve melachah (e.g., straightening up the house for Shabbos). Other preparations which involve melachah and are not food-related (e.g., carrying a machzor to shul on Friday for Shabbos through a public domain) are subject to dispute; therefore, it is preferable to make sure to derive benefit from it on Yom Tov itself.10

NOTE: It is important to stress that preparing the Eruv Tavshilin only permits actions which may be performed on Yom Tov and were prohibited merely because they were done in preparation for Shabbos. Actions which are prohibited to be done on Yom Tov (e.g., turning on and off lights and using electric appliances) are never permitted, even if an Eruv was prepared. Additionally, the Eruv Tavshilin only allows preparation for Shabbos; preparation for a weekday remains prohibited.


Who Needs to Prepare an Eruv Tavshilin?

Any household which intends to cook, bake, or even reheat food on Friday for Shabbos, must prepare an Eruv Tavshilin.11 Those who do not intend to do any food preparation may still need to prepare an Eruv for other preparations (see footnote).12

One Eruv is sufficient for all members of the household (Mishnah Berurah 527:56). A guest in a hotel or in someone’s home needs to prepare an Eruv and does not automatically become part of the household’s Eruv (see footnote).13


1 The rationale for this requirement is based on the following: Logic dictates that a Rabbinical institution, such as Eruv Tavshilin, may not override a Biblical prohibition; it is thus self-evident that the Eruv Tavshilin is only effective where there is no Biblical prohibition. As explained above, according to some opinions, cooking on Yom Tov for Shabbos may involve a Biblical prohibition. In order to accommodate these opinions, one must be careful to ensure that all food prepared on Friday is edible before Shabbos begins, thus avoiding the Biblical prohibition. However, in extenuating circumstances, one may rely on the other opinions which rule that preparing food for Shabbos does not involve a Biblical prohibition (ibid.).

2 According to most opinions, the main component of the Eruv is the cooked item – not the baked item – because the term “cooking” encompasses baking as well. However, in order to accommodate the position of some opinions which rule that baking is not included in the term cooking, one must set aside a baked item as well. If one set aside a baked item for the Eruv but failed to set aside a cooked item, the Eruv is not valid and must be prepared again in the proper way. If, however, one set aside a cooked item but failed to set aside a baked item, the Eruv is valid (Shulchan Aruch 527:2).

Nonetheless, if one remembers before the onset of Yom Tov that he forgot to set aside a baked item, he should take a baked item along with the cooked item and say the declaration again without repeating the bracha (Mishnah Berurah 527:7).

3 One explanation for this custom is that the Eruv must stay intact and edible until the preparations for Shabbos are finished. Accordingly, one must use a food item which does not spoil quickly, so the custom developed to use a hard-boiled egg, which satisfies this requirement (Aruch HaShulchan 527:13, Ben Ish Chai – Shanah 1, Tzav 1). As an aside, one should be careful to leave the egg in its shell because, according to many opinions, an egg should not be eaten if it was left overnight without its shell (see Aruch HaShulchan Y.D. 116:22). If the egg was shelled, it should be mixed with another food (e.g., mayonnaise) before the night passes.

4 See Biur Halacha, 527:6, s.v. adashim.

5 See Mishnah Berurah 527:40.

6 If the baked item was eaten (or ruined) before preparations for Shabbos took place but the cooked food is intact, Shabbos preparations may continue as usual (Mishnah Berurah 527:46). If, however, the cooked item was eaten, the Eruv is disqualified, unless a k’zayis of the food remains (Shulchan Aruch 527:15). If the Eruv is ruined or eaten while one is in the midst of food preparation, preparation of that particular food may be completed (ibid. 527:17).

7 Mishnah Berurah 527:48. The reason is that once an item is used for a mitzvah, it should be used for additional mitzvos (ibid.).

8 Rama 527:1. If doing so will cause one to miss the correct time to recite Mincha, he should appoint a messenger to make the Eruv on his behalf. Alternatively, he may give all the food items he wishes to prepare for Shabbos as a present to a friend who prepared an Eruv and ask the friend to cook and bake the food (Mishnah Berurah 527:4).

9 In extenuating circumstances, there is a possibility that one may be able to rely on the Rav’s Eruv. In addition, (a) on any 2-day Yom Tov other than Rosh Hashanah, there is an option to make the Eruv on the first day of Yom Tov with a t’nai – a condition (see Shulchan Aruch 527:22 for more details), and (b) one who forgets to prepare the Eruv may still light Shabbos candles but should only light one candle (Mishnah Berurah 527:55).

10 See Mishnah Berurah 302:17, Levush 528:2, Noda B’Yehuda Tinyana O.C. 25, and Kinyan Torah 3:70:2.

11 T’shuvos Shevet HaKahasi 2:184.

12 One who does not intend to heat or prepare food on Friday for Shabbos may still need to prepare the Eruv for other activities, such as lighting Shabbos candles or carrying items in a public domain. According to many Poskim, the Eruv should be prepared and the declaration recited, but the bracha should be omitted (Kaf HaChaim 527:113). Nevertheless, one who intends to light Shabbos candles and may possibly cook or bake for Shabbos should prepare the Eruv as normal (Chut Shani, Yom Tov pg. 150).

13 The guest may ask permission to join the household Eruv and pick up the Eruv food with intention to acquire a portion of the food prior to the Eruv setup. Alternatively, the guest may prepare his own Eruv but without a bracha (Chut Shani ibid. pg. 154). Guests who have been given free reign of the house and are welcome to help themselves to food and drink without specific permission (e.g., children visiting their parents’ home for Yom Tov) are likely included in the household Eruv.