סימן צה סעיף ח

יָכוֹל לִשְׁלוֹחַ אֶת הָעֵרוּב עַל יְדֵי שְּׁלִיחַ שֶׁיַּנִּיחֵהוּ בִּשְׁבִילוֹ, וִיבָרֵךְ הַשְּׁלִיחַ וְיֹאמַר, בָּזֶה הָעֵרוּב יְהֵא מֻתָּר לִפְלוֹנִי לֵילֵךְ וְכוּ'. וְצָרִיךְ שֶׁיְהֵא הַשְּׁלִיחַ גָּדוֹל וּבַר דַּעַת אֲבָל עַל יְדֵי קָטָן, אֵין שׁוֹלְחִין. וַאֲפִלּוּ לֹא חָזַר הַשְּׁלִיחַ אֶל מְשַׁלְּחוֹ, יָכוֹל לִסְמֹךְ עָלָיו, דַּחֲזָקָה שְּׁלִיחַ עוֹשֶׂה שְּׁלִיחַוּתוֹ (ת"ט).

You may send the eiruv with a messenger who will place it for you. The messenger should recite the berachah and then he should say: "By means of this eiruv it shall be permissible for so and so to walk etc. …"²³Alternatively you may say, “By means of this bread which my messenger is putting down for an eiruv, I will be allowed to walk from that place 2, 000 amos in each direction.” [Bi’ur Halachah 409: 8—Peri Megadim] The messenger must be bar mitzvah and of normal intelligence.²⁴The messenger must be a person who believes in the Rabbinically ordained mitzvos, for otherwise he will not put it down for the purpose of the eiruv. [see Sha’ar Hatziyun 409: 41] But you may not send [an eiruv] through a minor. Even if the messenger does not return to the sender, you may rely on him [to have fulfilled your mission], for we take it for granted²⁵This rule applies only to a Rabbinic halachah but not to a de’oraisa. [Tosafos (Maseches Eruvin 32a)] The Kitzur Shulchan Aruch evidently holds techumin is derabanan. that a messenger fulfills his mission.

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.)