סימן קב סעיף ו

כָּל בַּעַל הַבַּיִת צָרִיךְ לַעֲשׂוֹת עֵרוּב תַּבְשִׁילִין בְּעַצְמוֹ. וַאֲפִלּוּ אִשָּׁה שֶׁאֵין לָהּ בַּעַל, אִם יוֹדַעַת, מְחֻיֶּבֶת לַעֲשׂוֹת בְּעַצְמָהּ, וְאָסוּר לִסְמֹךְ עַל הָעֵרוּב שֶׁל גְּדוֹל הָעִיר. וּמִי שֶׁשָּׁכַח מֵחֲמַת אֹנֶס וְלֹא עָשָׂה עֵרוּב תַבְשִׁילִין, אוֹ שֶׁעָשָׂה וְנֶאֱבַד, אִם יֵשׁ בָּעִיר מִי שֶׁמְעָרֵב בִּשְׁבִיל כָּל בְּנֵי הָעִיר (דְּהַיְנוּ שֶׁמְזַכֶּה לָהֶם אֶת הַתַּבְשִׁיל וְאֶת הַפַּת, כַּמְבֹאָר בַּשֻּׁלְחָן עָרוּךְ) יָכוֹל זֶה לִסְמוֹךְ עַל עֵרוּב זֶה. אֲבָל מִי שֶׁשָּׁכַח מֵחֲמַת עַצְלוּת אוֹ שֶׁסָּמַךְ עַצְמוֹ לְכַתְּחִלָּה עַל עֵרוּב זֶה, לֹא מַהֲנִי לֵהּ וְדִינוֹ כְּדִלְעֵיל סָעִיף ה'.

The head of every household is required to make an eiruv tavshilin for himself. Even a woman who has no husband, if she knows how to make an eiruv tavshilin, is required to make one for herself. It is forbidden to rely on the eiruv made by the rabbi of the city. If, because of unavoidable circumstances, you forgot to make an eiruv tavshilin, or you made one, but it was lost, then if someone in the city makes an eiruv, for everyone in the city, (that is, he gives them a share in the cooked dish and the bread, as is explained in the Shulchan Aruch) you may rely on such an eiruv. But if you forgot out of laziness,²²If you deliberately relied on his eiruv, Shulchan Aruch 527:7 rules that it does not help. But Rambam, Rashba, Ran etc. say it does. Mishnah Berurah 527:26 rules that if your (simchas Yom Tov) rejoicing on Yom Tov, will be impaired, you, may be lenient and rely on this opinion. or if you meant to rely on this eiruv from the start, it is ineffective²³This applies also to a person who heard that he is obligated to make an eiruv tavshilin, but does not know how to make one. He should have asked someone to make it for him. Since he did not, he may not rely on someone else’s eiruv. (Radvaz 3:475) If he thought he was allowed to rely on someone else’s eiruv, he may rely on it, unless he is a Torah scholar and should have known better. (Shulchan Aruch Harav 527:14, Magein Avraham) and you must conduct yourself, according to the laws laid down in paragraph 5 above.

תנא דבי אליהו כל השונה הלכות בכל יום מובטח לו שהוא בן העולם הבא שנאמר הליכות עולם לו אל תקרי הליכות אלא הלכות (נדה ע"ג.)