MISHNA: 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.

GEMARA: Rabbi Yoḥanan says: I heard from those who travel to Usha to study with the Sages there that they would say: From where is it derived that presumptive ownership is established in three years? From the forewarned ox: Just as in the case of a forewarned ox, once it has intentionally gored three gorings, it left the presumptive status of an innocuous ox and it is established as having the presumptive status of a forewarned ox, here too, once he has worked and profited from the land for three years, the land left the possession of the seller, and it is established as being in the possession of the buyer.

The Gemara questions this comparison: If so, say that just as with a forewarned ox, the owner is not liable to pay full damages until the fourth goring, here too, the land should not be established as being in his possession until the fourth year. The Gemara rejects this question: How can these cases be compared? There, once it has gored three times it is forewarned,