Jerusalem Talmud Nedarim 2:3

משנה: יֵשׁ נֶדֶר בְּתוֹךְ נֶדֶר וְאֵין שְׁבוּעָה בְתוֹךְ שְׁבוּעָה. כֵּיצַד אָמַר הֲרֵינִי נָזִיר אִם אוֹכַל הֲרֵינִי נָזִיר אִם אוֹכַל וְאָכַל חַייָב עַל כָּל־אַחַת וְאַחַת. שְׁבוּעָה שֶׁלֹּא אוֹכַל שְׁבוּעָה שֶׁלֹּא אוֹכַל וְאָכַל אֵינוֹ חַייָב אֶלָּא אַחַת. MISHNAH: A vow inside a vow is possible, an oath inside an oath is impossible. For example, if one said, I shall be a nazir if I would eat, I shall be a nazir if I would eat, if he eats he is obligated for each pronouncement separately³⁷If he drinks wine after eating, he can be sentenced to two whippings. If he keeps his vow, he has to observe two 30-day periods of nezirut and bring two sets of sacrifices.. An oath that I will not eat, an oath that I will not eat, if he eats he is guilty only once³⁸If he breaks his oath, he can be punished only once..

הלכה: יֵשׁ נֶדֶר בְּתוֹךְ נֶדֶר כול׳. רִבִּי יוֹסֵי בָּעֵי. שְׁבוּעָה שְׁבוּעָה שְׁבוּעָה שֶׁלֹּא אוֹכַל. וְאָכַל. אָמַר רִבִּי יוֹסֵי בֵּירִבִּי בּוּן. נִישְׁמְּעִינָהּ מִן הָדָא. שְׁבוּעָה שֶׁלֹּא אוֹכַל כִכָּר זֶה. שְׁבוּעָה שֶׁלֹּא אוֹכַל. שְׁבוּעָה שֶׁלֹּא אוֹכַל. וְאָכַל. אֵינוֹ חַייָב אֶלָּא אַחַת. מִפְּנֵי שֶׁאָמַר זוֹ. הָא אִם לֹא אָמַר זוֹ חַייָב עַל כָּל־אַחַת וְאַחַת. אֲבִימֵי אַחֲוֵי דְחֵיפָה אָמַר שַׁמָּשִׁית בִּנְדָרִים שַׁמָּשִׁית בִּשְׁבוּעוֹת. בָּעֵי חֵיפָה מִיבְדְּקוּנֵיהּ. הָיוּ לְפָנָיו חֲמִשָּׁה כִּכָּרִים וְאָמַר. שְׁבוּעָה שֶׁאוֹכַל כִכָּר זוֹ. וְחָזַר וְאָמַר. שְׁנַיִם אֵילּוּ. וְחָזַר וְאָמַר. שְׁלֹשָׁה אֵילּוּ. וְחָזַר וְאָמַר. אַרְבָעָה אֵילּוּ. וְחָזַר וְאָמַר. חֲמִשָּׁה אֵילּוּ. וְאָכַל אֶת הָרִאשׁוֹן מָהוּ. אָמַר לֵיהּ. חַייָב עַל כָּל־אַחַת וְאַחַת. אָמַר לֵיהּ. אֵינוֹ חַייָב אֶלָּא אַחַת. מִכֵּיוָן שֶׁהִזְכִּיר עָלָיו שְׁבוּעָה עֲשָׂאוֹ כִנְבֵילָה. מִיכָּן וָאֵילַךְ כְּמֵיחַל שְׁבוּעוֹת עַל הָאִיסָּרִין. וְאֵין שְׁבוּעוֹת חָלוֹת עַל הָאִיסָּרִין. חָזַר וּבְדָקֵיהּ. הָיוּ חֲמִשָּׁה כִּכָּרִים וְאָמַר. שְׁבוּעָה חְמִשָּׁה כִכָּרִים הָאֵילּוּ. וְחָזַר וְאָמַר. אַרְבָּעָה אֵילּוּ. וְחָזַר וְאָמַר. שְׁלֹשָׁה אֵילּוּ. וְחָזַר וְאָמַר. שְׁנַיִם אֵילּוּ. וְחָזַר וְאָמַר. אֶחָד זֶה. וְאָכַל אֶת כּוּלָּן. אָמַר לֵיהּ. אֵינוֹ חַייָב אֶלָּא אַחַת. אָמַר לֵיהּ. חַייָב עַל כָּל־אַחַת וְאַחַת. אִילּוּ מִי שֶׁאָמַר. שְׁבוּעָה שֶׁאוֹכַל חֲמִשָּׁה. וְאָכַל אַרְבָּעָה. שֶׁמָּא אֵינוֹ פָטוּר. אָמַר רִבִּי יוֹסֵי. מִסְתַּבְּרָא כְּאַחֲוֵי דְחֵיפָה בָאַחֲרִיתָא. וּדְחֵיפָה בְקַדְמִיתָא. HALAKHAH: “A vow inside a vow is possible,” etc. ³⁹The entire Halakhah is also in Šebuot 3:8. Rebbi Yose asked: An oath, an oath, an oath that I shall not eat, but he ate? Rebbi Yose ben Rebbi Abun said, let us hear from the following⁴⁰Mishnah Šebuot 3:8.: “An oath that I shall not eat this loaf, an oath that I shall not eat, an oath that I shall not eat. If he ate, he is guilty only once.” Because he said this. Therefore, if he had not said this, he would be guilty for each of the oaths⁴¹This paragraph admits of two quite different interpretations. The first, by R. David Fraenckel, notes that in the question, the three oaths are mentioned before the object of the oath is specified, but in the Mishnah the object is specified before the second oath is pronounced. In the Mishnah, the second and third oaths are void since the loaf is already forbidden. But in R. Yose’s question, nothing is forbidden when the second and third oaths are pronounced; therefore, they all are valid and with one act the person who then eats the loaf commits three sins in one act.
The second, not very likely, explanation, by R. Moses Margalit, assumes that many loaves are before the person when he makes the multiple oath and one may assume that each single oath refers to a different loaf. Therefore, if he eats all of them he is guilty for each loaf separately since the Mishnah states only that if he expressly refers to the same loaf each time he swears, he is guilty only once.. ⁴²There is a parallel in the Babli, Šebuot 28b/29a. Avime the brother of Ḥefa⁴³In the Babli, he is called ‘Epha. In the Babli, where Avime is called “his brother”, Avime is the superior scholar. In the Munich ms., the notation “his brother” is missing. said, I studied vows, I studied oaths. Ḥefa wanted to examine him: There were five loaves before him and he said, an oath that I shall not eat this loaf. Then he said, these two loaves. Then he said, these three loaves. Then he said, these four loaves. Then he said, these five loaves. Then he ate the first, what are the rules? He said to him, he is guilty for each [oath] separately⁴⁴Assuming that the first loaf was included in every subsequent oath.. He said to him, he is guilty only once. From the moment he mentioned “oath” about it, he made it like carcass meat⁴Forbidden food, Deut. 14:21.. From there on he is as if he wanted to apply oaths to prohibitions, but no oath can be applied to prohibitions. He examined him a second time. There were five loaves and he said, an oath about these five loaves. Then he said, these four. Then he said, these three. Then he said, these two. Then he said, this single one. Then he ate all of them? He said to him, he is guilty only once. He said to him, he is guilty for each [oath] separately. If somebody had said, an oath that I shall not eat five, and he ate four, would he be free from punishment⁴⁵Since he did not keep his oath. But in Avime’s opinion, the first oath voids all the subsequent ones.? Rebbi Yose said, it is reasonable following Ḥefa’s brother in the last case, following Ḥefa in the first⁴⁶In no case can an oath be added to an oath..