אַב מְלָאכָה וּמְלָאכָה. הָעוֹשֶׂה מְלָאכוֹת הַרְבֵּה מֵעֵין מְלָאכָה אַחַת, אֵינוֹ חַיָּיב אֶלָּא חַטָּאת אַחַת. and every primary category of labor that he performed. One who performs numerous prohibited labors subsumed under a single category of labor is liable to bring only one sin-offering.

גְּמָ׳ מַאי טַעְמָא תְּנָא ״כְּלָל גָּדוֹל״? אִילֵּימָא מִשּׁוּם דְּקָבָעֵי לְמִיתְנֵי: ״עוֹד כְּלָל אַחֵר אָמְרוּ״, תְּנָא ״כְּלָל גָּדוֹל״. וְגַבֵּי שְׁבִיעִית נָמֵי, מִשּׁוּם דְּקָבָעֵי לְמִיתְנֵי: ״עוֹד כְּלָל אַחֵר אָמְרוּ״, תְּנָא ״כְּלָל גָּדוֹל״. וְהָא גַּבֵּי מַעֲשֵׂר, דְּקָתָנֵי: ״כְּלָל אַחֵר אָמְרוּ״, וְלָא תָּנֵי ״כְּלָל גָּדוֹל״! GEMARA: The Gemara attempts to clarify the language of the mishna and asks: Why did the mishna teach the phrase: A significant principle? If you say it is because of the following reason, it is problematic.
Here, because the tanna wants to teach in a mishna later in the chapter with regard to a matter that includes two halakhot employing the term: Furthermore, they stated another principle; therefore, in this mishna, which relates to a greater number of halakhot, he taught employing the term: A significant principle.
And with regard to the Sabbatical Year as well, because in a later mishna (Shevi’it 7:2) the tanna wants to teach: Furthermore, another principle, at the beginning of the chapter he taught employing the phrase: A significant principle. There too, the choice of language is understood.
However, with regard to the halakhot of tithes, where the mishna (Ma’asrot 1:1) states two principles one after the other, the tanna taught later in the same mishna: And furthermore, they stated another principle, and even so, at the beginning of the mishna the tanna did not teach: A significant principle, opting instead to say simply: They stated a principle.

אָמַר רַבִּי יוֹסֵי בַּר אָבִין: שַׁבָּת וּשְׁבִיעִית דְּאִית בְּהוּ אָבוֹת וְתוֹלָדוֹת — תְּנָא ״גָּדוֹל״, מַעֲשֵׂר דְּלֵית בֵּהּ אָבוֹת וְתוֹלָדוֹת, לָא תְּנָא ״כְּלָל גָּדוֹל״. וּלְבַר קַפָּרָא, דְּתָנֵי ״כְּלָל גָּדוֹל״ בְּמַעֲשֵׂר, מַאי אָבוֹת וּמַאי תּוֹלָדוֹת אִיכָּא? Rabbi Yosei bar Avin said that the term: A significant principle, is not dependent on the existence of another principle; rather, it is dependent on the significance of the principle. Therefore, with regard to the halakhot of Shabbat and the Sabbatical Year, which include primary categories and subcategories, the tanna taught in the mishna: A significant principle. With regard to the halakhot of tithes, which do not include primary categories and subcategories and all its halakhot are on equal footing, he did not teach employing the term: A significant principle. The Gemara asks: And according to the variant reading of the mishna taught by bar Kappara, who taught the phrase: A significant principle, with regard to tithes, what primary categories and subcategories are there with regard to tithes?

אֶלָּא לָאו הַיְינוּ טַעְמָא, גָּדוֹל עוֹנְשָׁהּ שֶׁל שַׁבָּת יוֹתֵר מִשֶּׁל שְׁבִיעִית, דְּאִילּוּ שַׁבָּת אִיתַהּ בֵּין בְּתָלוּשׁ בֵּין בִּמְחוּבָּר, וְאִילּוּ שְׁבִיעִית בְּתָלוּשׁ לֵיתַהּ בִּמְחוּבָּר אִיתַהּ. וְגָדוֹל עוֹנְשָׁהּ שֶׁל שְׁבִיעִית יוֹתֵר מִן הַמַּעֲשֵׂר, דְּאִילּוּ שְׁבִיעִית אִיתַהּ בֵּין בְּמַאֲכַל אָדָם בֵּין בְּמַאֲכַל בְּהֵמָה, וְאִילּוּ מַעֲשֵׂר בְּמַאֲכַל אָדָם אִיתֵהּ בְּמַאֲכַל בְּהֵמָה לֵיתֵהּ. Rather, isn’t this the reason the Mishna employs the term: A significant principle; because it is significant relative to other principles? The scope of the materials whose use warrants punishment for desecrating Shabbat is greater than the scope of the materials whose use warrants punishment for desecrating the Sabbatical Year. As the halakhot of Shabbat are in effect both with regard to plants that are detached from the ground and with regard to those that are attached, while the halakhot of the Sabbatical Year with regard to detached plants, they are not in effect, but with regard to attached plants they are in effect. And the scope of the materials whose use warrants punishment for desecration of the Sabbatical Year are greater than the scope of the materials whose use warrants punishment for violating the halakhot of tithes. As, by Torah law, the halakhot of the Sabbatical Year are in effect both with regard to human food and with regard to animal food, while the halakhot of tithes are in effect with regard to human food, but with regard to animal food they are not in effect.

אוֹכֶל — לְמַעוֹטֵי סְפִיחֵי סְטִיס וְקוֹצָה. וְנִשְׁמָר — לְמַעוֹטֵי הֶפְקֵר. וְגִידּוּלוֹ מִן הָאָרֶץ — לְמַעוֹטֵי כְּמֵיהִין וּפִטְרִיּוֹת. וּלְקִיטָתוֹ כְּאַחַת — לְמַעוֹטֵי תְּאֵנָה. וּמַכְנִיסוֹ לְקִיּוּם — לְמַעוֹטֵי יָרָק. The Gemara explains that which is excluded by each criterion in the mishna. Food, to exclude the aftergrowths of woad [satis] and madder. As these plants are used for dyeing and not for food, the obligation of pe’a does not apply to them. And protected, to exclude ownerless crops, which by definition are not protected. And grows from the ground, to exclude truffles and mushrooms, which, unlike other plants, do not draw sustenance from the ground. And is gathered as one, to exclude the fig tree whose fruit is gathered throughout an extended period, as the figs do not all ripen together. And one brings it in to storage to preserve; to exclude vegetables, which cannot be stored for lengthy periods.

וְאִילּוּ גַּבֵּי מַעֲשֵׂר תְּנַן, כְּלָל אָמְרוּ בַּמַּעֲשֵׂר: כׇּל שֶׁהוּא אוֹכֶל וְנִשְׁמָר וְגִידּוּלוֹ מִן הָאָרֶץ — חַיָּיב בְּמַעֲשֵׂר. וְאִילּוּ לְקִיטָתוֹ כְּאַחַת וּמַכְנִיסוֹ לְקִיּוּם לָא תְּנַן. While, with regard to tithes, we learned in a mishna: They stated a principle with regard to tithes: Anything that is food, and is protected, and grows from the ground is obligated in tithes; we did not learn with regard to tithes, the following criteria: Gathered as one, and which one brings in to storage to preserve. Apparently, figs and vegetables are obligated in tithes, making the scope of the materials obligated in tithes greater than the scope of those obligated in pe’a.

רַב וּשְׁמוּאֵל דְּאָמְרִי תַּרְוַיְיהוּ: מַתְנִיתִין בְּתִינוֹק שֶׁנִּשְׁבָּה לְבֵין הַגּוֹיִם, וְגֵר שֶׁנִּתְגַּיֵּיר לְבֵין הַגּוֹיִם. אֲבָל הִכִּיר וּלְבַסּוֹף שָׁכַח — חַיָּיב עַל כׇּל שַׁבָּת וְשַׁבָּת. תְּנַן: ״הַשּׁוֹכֵחַ עִיקַּר שַׁבָּת״, לָאו מִכְּלָל דְּהַוְיָא לֵיהּ יְדִיעָה מֵעִיקָּרָא?! לָא, מַאי ״כׇּל הַשּׁוֹכֵחַ עִיקַּר שַׁבָּת״ — שֶׁהָיְתָה שְׁכוּחָה מִמֶּנּוּ עִיקָּרָהּ שֶׁל שַׁבָּת. The mishna discusses an individual who forgets the very essence of Shabbat. The Gemara seeks to understand how a Jew could forget the very existence of Shabbat. It was Rav and Shmuel who both said: Our mishna is referring to both a child who was taken captive among the gentiles and never educated and a convert who converted among the gentiles and never learned the halakhot of Shabbat. However, one who once knew of the essence of Shabbat and ultimately forgot is liable for each and every Shabbat, as we learned in the mishna with regard to one who knows the essence of Shabbat. The Gemara seeks to clarify this approach. We learned in our mishna: One who forgets the essence of Shabbat. Doesn’t this phrase indicate by inference that he was aware of Shabbat originally? In order to forget one must have previously been aware. This poses a difficulty to the opinion of Rav and Shmuel. The Gemara refutes this: No, what is the meaning of: One who forgets the essence of Shabbat? That the essence of Shabbat was always forgotten from him, i.e., he never knew it.

אֲבָל הִכִּיר וּלְבַסּוֹף שָׁכַח מַאי — חַיָּיב עַל כׇּל שַׁבָּת וְשַׁבָּת? אַדְּתָנֵי הַיּוֹדֵעַ עִיקַּר שַׁבָּת וְעָשָׂה מְלָאכוֹת הַרְבֵּה בְּשַׁבָּתוֹת הַרְבֵּה חַיָּיב עַל כׇּל שַׁבָּת וְשַׁבָּת, לִיתְנֵי ״הִכִּיר וּלְבַסּוֹף שָׁכַח״, וְכׇל שֶׁכֵּן הָא! מַאי ״הַיּוֹדֵעַ עִיקַּר שַׁבָּת״ — מִי שֶׁהָיָה יוֹדֵעַ עִיקָּרָהּ שֶׁל שַׁבָּת וּשְׁכֵחָהּ. The Gemara further asks: However, based on that understanding, in the case of one who knew the essence of Shabbat and ultimately forgot, what is the halakha? Is he liable for each and every Shabbat? If so, instead of the mishna teaching the next halakha: One who knows the essence of Shabbat and performs many labors on multiple Shabbatot is liable to bring a sin-offering for each and every Shabbat, let it teach: One who knew the essence of Shabbat and ultimately forgot and, all the more so, one who knows the essence of Shabbat would be liable for each Shabbat. The Gemara answers: According to the opinion of Rav and Shmuel, what is the meaning of the phrase: One who knows the essence of Shabbat? One who once knew the essence of Shabbat and has now forgotten it.