Commentary for Horayot 1:2
הוֹרוּ בֵית דִּין, וְיָדְעוּ שֶׁטָּעוּ, וְחָזְרוּ בָהֶן, בֵּין שֶׁהֵבִיאוּ כַפָּרָתָן וּבֵין שֶׁלֹּא הֵבִיאוּ כַפָּרָתָן, וְהָלַךְ וְעָשָׂה עַל פִּיהֶן, רַבִּי שִׁמְעוֹן פּוֹטֵר, וְרַבִּי אֱלִיעֶזֶר אוֹמֵר, סָפֵק. אֵיזֶהוּ סָפֵק. יָשַׁב לוֹ בְתוֹךְ בֵּיתוֹ, חַיָּב. הָלַךְ לוֹ לִמְדִינַת הַיָּם, פָּטוּר. אָמַר רַבִּי עֲקִיבָא, מוֹדֶה אֲנִי בָזֶה שֶׁהוּא קָרוֹב לִפְטוּר מִן הַחוֹבָה. אָמַר לוֹ בֶן עַזַּאי, מַה שָּׁנָה זֶה מִן הַיּוֹשֵׁב בְּבֵיתוֹ, שֶׁהַיּוֹשֵׁב בְּבֵיתוֹ אֶפְשָׁר הָיָה לוֹ שֶׁיִּשְׁמַע, וְזֶה לֹא הָיָה אֶפְשָׁר לוֹ שֶׁיִּשְׁמָע:
If beth-din ruled (wrongly) and they discovered that they had erred and retracted — whether they had brought their atonement or had not yet brought their atonement, and one went and transgressed by their (original) ruling — R. Shimon exempts him (from an offering) and R. Eliezer says: It is a safek (a doubt). [Since he should have asked all the time about news of the rulings in beth-din and did not do so, his case is similar to that of one who is in doubt as to whether he sinned or did not sin, in which instance he brings a suspended guilt-offering (asham talui). The halachah is in accordance with R. Eliezer.] Which is the safek? [i.e., In which instance does R. Eliezer say that he is judged as one who is in doubt as to whether or not he sinned and is liable to bring an asham talui?] If he sat in his house, he is liable [i.e., if he sat in his house in the country in which beth-din ruled, in which instance he could have heard that beth-din had retracted.] But if he went abroad, he is exempt [not only if he actually went, but if he was on the way to go, even if he had not actually gone. R. Akiva said: I concede in this instance that he is close to being exempt from liability. Ben Azzai said to him: How is this different from sitting in one's house? [R. Akiva answered:] The one sitting in his house could have heard, but the other could not have heard. [R. Akiva holds that because of his preoccupation with going, he does not ask if beth-din had retracted, and he is exempt from an asham talvi. And Ben Azzai holds that since he had not yet gone, he should have asked. On this hinges the argument in the Gemara. The halachah is in accordance with R. Akiva.]
Bartenura on Mishnah Horayot
English Explanation of Mishnah Horayot
Which case may be regarded doubtful? If he was at home, he is liable. If he went abroad, he is exempt.
Rabbi Akiba said: I agree that a person in such a case is nearer to exemption than to culpability. Said Ben Azzai to him: how does such a person differ from one who remains at home? He who remains at home is in a position to ascertain the facts but the other was not in such a position.
This mishnah discusses a case where a court made a wrong decision and then reversed their decision, thereby correcting it. The question asked is whether or not one who follows the wrong decision after it has been revoked is exempt from bringing a sin-offering for his accidental transgression.
Section one: The offering referred to in this section will be discussed more fully below in mishnah five, specifically the question of who brings the sacrifice.
Rabbi Shimon exempts this person because he relied on the court. As we learned above in mishnah one, a person who relies on the court is exempt from bringing an individual sin-offering. Rabbi Elazar declares this case doubtful, for we do not know if he had already heard that the court had reversed its decision.
The mishnah now continues to discuss in which specific cases the matter is in doubt. If the person was at home and could have known that the court reversed its decision, he is responsible for not having followed the new decision. However, if he had gone abroad, he could not have known of the reversal, and he is therefore exempt.
Rabbi Akiva states that this person, who went abroad, is actually closer to being totally exempt, for it is very unlikely that he knew that the court reversed its decision. As he explains to Ben Azzai, his colleague, the person sitting in his house could have heard, whereas the one who was abroad could not have.