בס"ד
  1. משנה בבא בתרא ג׳:א׳

    (א) חֶזְקַת הַבָּתִּים וְהַבּוֹרוֹת וְהַשִּׁיחִין וְהַמְּעָרוֹת וְהַשּׁוֹבָכוֹת וְהַמֶּרְחֲצָאוֹת וּבֵית הַבַּדִּין וּבֵית הַשְּׁלָחִין וְהָעֲבָדִים וְכָל שֶׁהוּא עוֹשֶׂה פֵרוֹת תָּדִיר, חֶזְקָתָן שָׁלֹשׁ שָׁנִים מִיּוֹם לְיוֹם. שְׂדֵה הַבַּעַל, חֶזְקָתָהּ שָׁלֹשׁ שָׁנִים, וְאֵינָהּ מִיּוֹם לְיוֹם, רַבִּי יִשְׁמָעֵאל אוֹמֵר, שְׁלֹשָׁה חֳדָשִׁים בָּרִאשׁוֹנָה וּשְׁלֹשָׁה בָּאַחֲרוֹנָה וּשְׁנֵים עָשָׂר חֹדֶשׁ בָאֶמְצַע, הֲרֵי שְׁמֹנָה עָשָׂר חֹדֶשׁ. רַבִּי עֲקִיבָא אוֹמֵר, חֹדֶשׁ בָּרִאשׁוֹנָה וְחֹדֶשׁ בָּאַחֲרוֹנָה וּשְׁנֵים עָשָׂר חֹדֶשׁ בָּאֶמְצַע, הֲרֵי אַרְבָּעָה עָשָׂר חֹדֶשׁ. אָמַר רַבִּי יִשְׁמָעֵאל, בַּמֶּה דְבָרִים אֲמוּרִים, בִּשְׂדֵה לָבָן. אֲבָל בִּשְׂדֵה אִילָן, כָּנַס אֶת תְּבוּאָתוֹ, מָסַק אֶת זֵיתָיו, כָּנַס אֶת קֵיצוֹ, הֲרֵי אֵלּוּ שָׁלֹשׁ שָׁנִים:

    Mishnah Bava Batra 3:1

    (1) With regard to the presumptive ownership of houses; and of pits; and of ditches; and of caves, which are used to collect water; and of dovecotes; and of bathhouses; and of olive presses; and of irrigated fields, which must be watered by people; and of slaves; and all similar property that constantly, i.e., throughout the year, generates profits, their presumptive ownership is established by working and profiting from them for a duration of three years from day to day. If the one in possession of the property can prove that he worked and profited from it for the previous three full years, there is a presumption that it belongs to him, and would remain in his possession if another were to claim that the property belonged to him or to his ancestors. With regard to a non-irrigated field, i.e., one that is watered by rain, in which produce grows during certain seasons during the year, its presumption of ownership is established in three years, but they are not from day to day, since the fields are not worked and harvested continually throughout the three-year period. Rabbi Yishmael says: Three months of possession in the first year, three months of possession in the last year, and twelve months of possession in the middle, which are eighteen months, suffice to establish the presumption of ownership with regard to a non-irrigated field. Rabbi Akiva says: A month of possession in the first year, and a month of possession in the last year, and twelve months of possession in the middle, which are fourteen months, suffice to establish the presumption of ownership with regard to a non-irrigated field. Rabbi Yishmael said: In what case is this statement, that eighteen months are required for a non-irrigated field, said? It is said with regard to a white field [bisdeh lavan], i.e., a grain field. But with regard to a field of trees, once he gathered his produce, and then harvested his olives, and then gathered his figs, these three harvests are the equivalent of three years. Since he harvested three types of produce, this is equivalent to having possessed the field for three years.