Commentary for Keritot 4:2
כְּשֵׁם שֶׁאִם אָכַל חֵלֶב וְחֵלֶב בְּהֶעְלֵם אֶחָד אֵינוֹ חַיָּב אֶלָּא חַטָּאת אַחַת, כָּךְ עַל לֹא הוֹדַע שֶׁלָּהֶן אֵינוֹ מֵבִיא אֶלָּא אָשָׁם אֶחָד. אִם הָיְתָה יְדִיעָה בֵינְתַיִם, כְּשֵׁם שֶׁהוּא מֵבִיא חַטָּאת עַל כָּל אַחַת וְאַחַת, כָּךְ הוּא מֵבִיא אָשָׁם תָּלוּי עַל כָּל אַחַת וְאֶחָת. כְּשֵׁם שֶׁאִם אָכַל חֵלֶב וְדָם נוֹתָר וּפִגּוּל בְּהֶעְלֵם אֶחָד, חַיָּב עַל כָּל אֶחָד וְאֶחָד, כָּךְ עַל לֹא הוֹדַע שֶׁלָּהֶן מֵבִיא אָשָׁם תָּלוּי עַל כָּל אֶחָד וְאֶחָד. חֵלֶב וְנוֹתָר לְפָנָיו, אָכַל אַחַד מֵהֶם וְאֵין יָדוּעַ אֵיזֶה מֵהֶם אָכַל. אִשְׁתּוֹ נִדָּה וַאֲחוֹתוֹ עִמּוֹ בַבַּיִת, שָׁגַג בְּאַחַת מֵהֶן וְאֵין יָדוּעַ בְּאֵיזוֹ מֵהֶן שָׁגָג. שַׁבָּת וְיוֹם הַכִּפּוּרִים וְעָשָׂה מְלָאכָה בֵּין הַשְּׁמָשׁוֹת וְאֵין יָדוּעַ בְּאֵיזֶה מֵהֶם עָשָׂה. רַבִּי אֱלִיעֶזֶר מְחַיֵּב חַטָּאת, וְרַבִּי יְהוֹשֻׁעַ פּוֹטֵר. אָמַר רַבִּי יוֹסֵי, לֹא נֶחְלְקוּ עַל הָעוֹשֶׂה מְלָאכָה בֵּין הַשְּׁמָשׁוֹת, שֶׁהוּא פָטוּר, שֶׁאֲנִי אוֹמֵר, מִקְצָת מְלָאכָה עָשָׂה מֵהַיּוֹם, וּמִקְצָתָהּ לְמָחָר. וְעַל מַה נֶּחְלְקוּ, עַל הָעוֹשֶׂה בְּתוֹךְ הַיּוֹם וְאֵין יָדוּעַ אִם בְּשַׁבָּת עָשָׂה וְאִם בְּיוֹם הַכִּפּוּרִים עָשָׂה. אוֹ עַל הָעוֹשֶׂה וְאֵין יָדוּעַ מֵעֵין אֵיזוֹ מְלָאכָה עָשָׂה. רַבִּי אֱלִיעֶזֶר מְחַיֵּב חַטָּאת, וְרַבִּי יְהוֹשֻׁעַ פּוֹטֵר. אָמַר רַבִּי יְהוּדָה, פּוֹטְרוֹ הָיָה רַבִּי יְהוֹשֻׁעַ אַף מֵאָשָׁם תָּלוּי:
Just like a person who ate forbidden fat twice under one spell of unawareness is liable for only one <i>Chattat</i> [an offering brought to expiate sin], so too, when they are not known [the individual is not certain he sinned], he is liable for only one <i>Asham Talui</i>. If he became aware in the interim [between the two acts, that he might have sinned] he brings a separate <i>Asham Talui</i> for each [act], just as he would bring a separate <i>Chattat</i> for each [act]. Just like if one ate forbidden fat, and blood, and <i>Notar</i> [a sacrifice that becomes unfit due to being unconsumed past the permitted time], and <i>Piggul</i> [a sacrifice that becomes unfit due to the intention of the officiating priest while offering it, to consume it after its permitted time] under one spell of unawareness, he is liable for [a <i>Chattat</i>] for each one; so too, when they are not known, one brings a separate <i>Asham Talui</i> for each [forbidden food]. [If] forbidden fat and <i>Notar</i> [sat] before an individual and he ate one of them but does not know which one of them he ate; [or if] one's <i>Niddah</i> [a woman who has menstruated and is thereby impure] wife and his sister were with him in his house, and he unthinkingly had relations with one of them and does not know with whom he unthinkingly had relations; [or if] Shabbat and Yom Kippur [fell on consecutive days] and one performed <i>Melakhah</i> at dusk [between the days] and does not know on which day he acted: Rabbi Eliezer deems [him] liable for a <i>Chattat</i>, but Rabbi Yehoshua exempts [him]. Rabbi Yose said: They do not disagree that [a person] who did <i>Melakhah</i> at dusk is exempt since I can say that he performed part of the <i>Melakhah</i> on one day and part on the following day. About what do they disagree? About one who did <i>Melakhah</i> during the day [itself] but does not know whether he did it on Shabbat or he did it on Yom Kippur; or where he did [<i>Melakhah</i>] and does not know what category the <i>Melakhah</i> he did [falls into]: Rabbi Eliezer deems him liable for a <i>Chattat</i>, but Rabbi Yehoshua exempts [him]. Rabbi Yehudah said:Rabbi Yehoshua even exempts him from an <i>Asham Talui</i>
Bartenura on Mishnah Keritot
English Explanation of Mishnah Keritot
If in the meantime he became aware [of the possible sin] he is liable to a separate asham talui for each act, just as he would [in similar circumstances] be liable to a separate hatat for each act.
Just as one is liable to separate hatats if he ate, in one spell of unawareness, forbidden fat and blood and piggul and notar, so, too, when the transgression is in doubt, he is liable to an asham talui for each different act.
[If both] forbidden fat and notar lay before a person and he ate one of them but does not know which;
Or if his menstruant wife and his sister were with him in his house and he has sex unwittingly with one of them and does not know with which,
Or if Shabbat and Yom Kippur [followed each other] and he did forbidden work at twilight and does not know on which day: Rabbi Eliezer declares him liable to a hatat; But Rabbi Joshua exempts him.
Rabbi Yose said: they did not dispute about a person that did work at twilight, for he is certainly exempt, for I may assume that part of the work was done on the one day and part on the following day.
About what did they dispute? About one who did work during the day itself but he did not know whether he did it on Shabbat or on Yom Kippur, or if he did work and did not know what manner of work he did: Rabbi Eliezer declares him liable to a hatat; But Rabbi Joshua exempts him. Rabbi Judah said: Rabbi Joshua exempts him even from an asham talui.
Today’s mishnah deals with two issues. The first part deals with multiple sins performed in one spell of unawareness. The second part deals with cases where a person definitely sinned, but he is not sure which of two possible sins he committed.
Section one: If a person eats many pieces of helev (forbidden fat) during one period of unawareness, for instance, he didn’t know that what he was eating was helev, or he didn’t know that helev was prohibited, he is liable for only one hatat. This counts as one sin, since it was done in one period of unawareness. Similarly, if in one period of unawareness he is not sure if he ate helev or something else, he is liable for only one asham talui, even if he did the act multiple times.
Section two: If in between sessions of eating something that might or might not be helev he finds out that it is perhaps helev, he is liable for an asham talui for each session. For instance he sits down to dinner and eats. Then his wife tells him, “Honey, that fat you just ate might have been helev.” He is now liable for an asham talui. If the same thing happens the next night, he is liable for two asham talui’s. This is the same rule that applies to cases where he knows that what he ate was helev he is obligated for one hatat for each period of unawareness.
Section three: If one eats foods that carry different prohibitions, one is liable for a hatat for each prohibition, if he knows he transgressed, and an asham talui for each transgression, if he is not sure that he transgressed. I.e. she sits down to dinner and when she is done her husband tells her, “Dear, you might just have eaten helev, blood and notar (remnant).” She is liable for three asham talui’s. If he said, “Dear, you ate helev, blood and notar,” she is liable for three hatats.
Sections 4-6: The second half of the mishnah is patterned after mishnah one. In that case, the person might have transgressed or he might not have transgressed. In the cases mentioned here he definitely transgressed, but he doesn’t know which transgression he did what forbidden food did he eat, which forbidden woman did he have sex with or what day did he do the forbidden labor on?
Rabbi Eliezer says that since he definitely did a forbidden act, he must bring a hatat, even though he is not sure what he actually did. We can see that Rabbi Eliezer adopts a more realistic approach one who certainly sins must bring a hatat.
Rabbi Joshua says that since he doesn’t know what he actually did, he is exempt. This seems to me to be more of a “nominal” approach. Since we cannot find a legal category under which to place his sin, we cannot make him liable.
Section seven: Rabbi Yose says that even Rabbi Eliezer would agree that if one does a sin at twilight between Shabbat and Yom Kippur he is exempt, because he might not have transgressed at all. It is possible that he did half of the prohibited labor on Shabbat and half on Yom Kippur, in which case he did not perform a forbidden labor on either day.
Rather the debate was over one who simply does not know whether he did the labor on Shabbat or on Yom Kippur, or knows that he performed a forbidden labor, but doesn’t know which labor it was. In this case Rabbi Eliezer makes him liable, for her certainly transgressed, even though we can’t find a legal category under which to place his transgression.
Section eight: Finally, Rabbi Judah explains that when Rabbi Joshua exempted him, he exempted him even from the asham talui. An asham talui is brought only in a case where a person might have sinned. Since this person definitely sinned, he cannot bring an asham talui. He is left without any sacrifice to bring.