7) It is customary for the Rav of the city (or community) to make an ET on behalf of others. This does not give people license to rely on his ET as a matter of course. The Rav’s ET covers only those people who fit into one of the following categories:
a) One who forgot one time to make an ET. It does not cover someone who had previously forgotten and did not learn from his mistake, and forgot again! (This is considered negligent!)
b) One who could not make an ET due to circumstances beyond his control (Heb. ‘oness’) c) One who did prepare an ET, but it was lost or destroyed d) One who is unlearned and does not know about the requirement to make an ET.
e) One who knows about ET, but is under the erroneous impression that he is permitted to rely on the Rav’s ET. Of course, once he discovers the truth he is no longer covered!
(Note: The Mishnah Berura cites a more lenient opinion that one is permitted to rely on the Rav’s ET as a matter of course. While this is not the halacha, a Rav may possibly use this opinion as basis for leniency, for the sake of ‘simchas (celebration of) Yom Tov’, even outside of the above categories. Of course, a ‘shaila’ must be asked!)
8) The Rav’s ET automatically covers (as per the conditions stated above) anyone within the halachic boundaries of his city, and even beyond the city limits as far as the end of the ’techum’ (i.e. the 2000-amah/cubit extension of the city – approximately 6/10 of a mile.) If the Rav intended to include someone outside of the ‘techum’, that person (or persons) could also rely on the Rav’s ET, provided that the person/persons had made an ‘Eruv Techumim’ before Yom Tov – i.e. a different kind of Eruv which permits one to travel into the ‘techum’ of a city from his place of residence on Shabbos and Yom Tov.
9) The Rav must have the city residents in mind at the time he makes the ET. In contrast, those relying on his ET need not be aware of the Rav’s ET at the time of its making; rather only from the time they would actually be using it – i.e. preparing for Shabbos on Friday/Yom Tov. So, for example, if someone was not aware that there was a Rav in his area who made an ET, and learned after Yom Tov started that there was, he could still rely on that Rav’s ET.
10) The Rav who is making the ET on behalf of others must legally transact a ‘kinyan’ (act of transfer of ownership) with the food items when making the ET. This must be done through the agency of a qualified person (e.g. Bar- or Bas Mitzvah who is not a financial dependent of the Rav). The agent must take the ET items in his hand and raise them up in the air at least one tefach (3-4 inches) high, with the intention of “acquiring” the ET on behalf of the people who are eligible to rely upon it.
11) After the ‘kinyan’ is made, the Rav proceeds to make the ET declaration, just as anyone would when making an ET for his own household. The text of this declaration can be found in most siddurim. It is important that a person understand the words he is saying, which means that it may be necessary to read it in English (or other language he understands.) We will quote the translation found in the Artscroll Siddur, p. 655. (Note: Prior to the declaration, a bracha is recited, as shown there.) “Through this eruv may we be permitted to bake, cook, insulate, kindle flame, prepare and do anything necessary on the Festival for the sake of Shabbos (the Rav adds:) …for ourselves and for all Jews who live in this city.”