(Devarim, Ibid. 12) "When you finish tithing": I might think on Channukah; it is, therefore, written here (Ibid. 14:28) "at the end," and elsewhere (Ibid. 31:10) "at the end." Just as "at the end" there signifies a festival, so, "at the end" here signifies a festival. — But why not say, then: Just as "at the end" there signifies the festival of Succoth, so, here, the festival of Succoth is signified! It is, therefore, written (Ibid. 26:12) "When you finish tithing" — the festival when all the tithes have been finished — Pesach. From here they ruled: On the eve of the last day of Pesach of the fourth year and the seventh year, there took place the removal (from the house [biur] of the tithes): on the fourth year, by reason of the poor-tithe of the third year; and on the seventh year, by reason of the poor-tithe of the sixth year. I might think that the (produce of) the seventh year (shemitah), too, is subject to removal; it is, therefore, written (Ibid.) "in the third year," a year which is subject to tithing, excluding the seventh year, which is not subject to tithing. I might think that two tithes both first-tithe and second-tithe (along with poor-tithe) obtain on it (the third year); it is, therefore, written (of the third year), (Ibid.) "the year of the (one) tithe." One tithe obtains on it and not two. I might think that only the poor-tithe, of which the verse speaks, is signified. Whence do I derive the other tithes (for inclusion)? From "all the tithe of your produce."
(דברים כו יב) כִּי תְכַלֶּה לַעְשֵׂר, יָכוֹל בַּחֲנֻכָּה? הֲרֵי אַתָּה דָּן: נֶאֱמַר כָּאן קֵץ וְנֶאֱמַר לְהַלָּן (דברים לא ז) קֵץ, מַה קֵץ הָאָמוּר לְהַלָּן רֶגֶל, אַף קֵץ הָאָמוּר כָּאן רֶגֶל. אִי מַה קֵץ הָאָמוּר לְהַלָּן חַג הַסֻּכּוֹת, אַף קֵץ הָאָמוּר כָּאן חַג הַסֻּכּוֹת? תַּלְמוּד לוֹמַר: כִּי תְכַלֶּה לַעְשֵׂר, רֶגֶל שֶׁהַמַּעַשְׂרוֹת כָּלִים בּוֹ, הֱוֵי אוֹמֵר זֶה פֶּסַח. מִכָּן אָמְרוּ: עֶרֶב יוֹם טוֹב הָאַחֲרוֹן שֶׁל פֶּסַח שֶׁל רְבִיעִית וְשֶׁל שְׁבִיעִית הָיָה הַבִּעוּר. בַּשָּׁנָה הַשְּׁלִישִׁית, יָכוֹל אַף שְׁנַת שָׁבוּעַ תְּהֵא חַיֶּבֶת בְּמַעֲשֵׂר? תַּלְמוּד לוֹמַר: בַּשָּׁנָה הַשְּׁלִישִׁת שְׁנַת הַמַּעֲשֵׂר, שָׁנָה שֶׁחַיֶּבֶת בְּמַעֲשֵׂר, יָצָאת שְׁנַת שָׁבוּעַ שֶׁאֵינָהּ חַיֶּבֶת בְּמַעֲשֵׂר. יָכוֹל יְהוּ שְׁנֵי מַעַשְׂרוֹת נוֹהֲגִים בָּהּ? תַּלְמוּד לוֹמַר: שְׁנַת הַמַּעֲשֵׂר, מַעֲשֵׂר אֶחָד נוֹהֵג בָּהּ וְאֵין שְׁנֵי מַעַשְׂרוֹת נוֹהֲגִים בָּהּ. אֵין לִי אֶלָּא מַעְשַׂר עָנִי שֶׁבּוֹ דִּבֶּר הַכָּתוּב, מִנַּיִן לְרַבּוֹת שְׁאָר מַעַשְׂרוֹת? תַּלְמוּד לוֹמַר: מַעְשַׂר תְּבוּאָתְךָ, רִבָּה.
(Devarim, Ibid. 12) "When you finish tithing": I might think on Channukah; it is, therefore, written here (Ibid. 14:28) "at the end," and elsewhere (Ibid. 31:10) "at the end." Just as "at the end" there signifies a festival, so, "at the end" here signifies a festival. — But why not say, then: Just as "at the end" there signifies the festival of Succoth, so, here, the festival of Succoth is signified! It is, therefore, written (Ibid. 26:12) "When you finish tithing" — the festival when all the tithes have been finished — Pesach. From here they ruled: On the eve of the last day of Pesach of the fourth year and the seventh year, there took place the removal (from the house [biur] of the tithes): on the fourth year, by reason of the poor-tithe of the third year; and on the seventh year, by reason of the poor-tithe of the sixth year. I might think that the (produce of) the seventh year (shemitah), too, is subject to removal; it is, therefore, written (Ibid.) "in the third year," a year which is subject to tithing, excluding the seventh year, which is not subject to tithing. I might think that two tithes both first-tithe and second-tithe (along with poor-tithe) obtain on it (the third year); it is, therefore, written (of the third year), (Ibid.) "the year of the (one) tithe." One tithe obtains on it and not two. I might think that only the poor-tithe, of which the verse speaks, is signified. Whence do I derive the other tithes (for inclusion)? From "all the tithe of your produce."