(Mishnah): To make a Chazakah (to become established to be the owner, to be believed to say that he bought the property and lost the purchase document) on any of the following, one must act like the owner for three complete years, to the day: pits of all shapes, caves, dovecotes, bathhouses, olive presses, irrigated fields, slaves, and anything that constantly produces;

One makes a Chazakah in a field that does not need to be irrigated in three incomplete years;

R. Yishmael says, the Chazakah can be made in 18 months: the last three months of the first year, the entire second year, and the first three months of the third year;

R. Akiva says, the Chazakah can be made in 14 months: the last month of the first year, the entire second year, and the first month of the third year.

R. Yishmael: This applies only to a grain field; but in an orchard, if one gathered the grapes, harvested the olives, and collected the dates drying in the field, this is like a Chazakah of three years.

(Gemara - R. Yochanan): I heard from members of the Sanhedrin that was exiled to Usha, that a Chazakah after three years of usage is learned from the law of a Mu'ad ox (an established gorer).

Just like an ox that gores three times changes its status from Tam to Mu'ad, likewise, if one claims that he bought a field and is Machazik (benefits from it) for three years, it changes from being assumed to belong to the Muchzak (original owner), and is established to belong to the Machazik.

Suggestion: We should say that just like an ox does not become Mu'ad until the fourth goring, also one is not Machazik in a field until the fourth year of benefit!

Rejection: This comparison is wrong! Once it gores three times, it is Mu'ad, just there is nothing to pay for until the fourth goring;

Regarding a field, after three years of benefit, the buyer is Muchzak.

Question: If we learn from a Mu'ad, a Chazakah without a claim (of how the field came to his hand) should be valid, but this is not so!

(Mishnah): A Chazakah without a claim is invalid.

Answer: Chazakah works because when a Machazik (one who took possession) claims that he bought a field and lost the document, and the Muchzak denies this, the Machazik's claim is more credible, since an owner is not silent when a thief benefits from his land for three years.

However, if the Machazik has no claim of ownership, should we claim for him?!

Question (Rav Avira): If we learn from a goring ox, a protest (by the Muchzak that the Machazik does not own it, which obligates the Machazik to guard his document of purchase) should be valid only in front of the Machazik!

Just like an ox only becomes a Mu'ad (which obligates its owner to pay more for its damage) if the owner was present three times when witnesses testified of its gorings, here also, the Machazik must be present at the protest!

Answer: Regarding a Mu'ad, the Torah decreed "v'Hu'ad bi'V'alav." Regarding Chazakah, those who hear the protest will tell their friends, who will tell their friends, and the Machazik will surely find out.

Question: R. Meir says that if it becomes Mu'ad for goring three times over three days (or more), all the more so it becomes Mu'ad for three gorings on one day;

If we learn Chazakah from a Mu'ad, he should say 'if one harvests three times in one day, such as a fig tree (different parts of the tree can ripen over the course of the day), this should count as a Chazakah!

Answer: No, Chazakah must resemble a Mu'ad.

Regarding an ox, at the time of one goring, the other gorings are not there. One must eat from three harvests, and at the time of each harvest, the fruits of the other harvests are not there.

Question: A caperbush can produce new fruit in three days (Rashi; Tosfos - each day; Aruch - three (new) fruits in one day). This should enable one to make a Chazakah very quickly!

Answer: No. There also, the later fruit is there when he eats the first fruit, just it is not finished.

Question: One can make three harvests of fodder in 30 days. This should make a Chazakah!

Question: How is this possible?

Answer: He cuts it after it only grows a little.

Answer: Since he is not harvesting the full fruit, this does not make Chazakah.

Question: One can make three harvests of (fully grown) fodder in three months. This should make a Chazakah!

Answer: R. Yochanan heard his law from members of the Sanhedrin that was exiled to Usha, i.e. R. Yishmael; indeed, R. Yishmael says that a Chazakah can be made so quickly!

(Mishnah - R. Yishmael): Three years are needed for a grain field; but for an orchard, if one gathered the Peros (grapes), the olives, and the figs, this is like three years (of Chazakah).

Question: What is Chachamim's source for three years of Chazakah?

Answer #1 (Rav Yosef): "Sados ba'Kesef Yiknu v'Chasuv ba'Sefer v'Chasum." The Navi told people in the tenth year that they will be exiled in the eleventh (and will only have two years on the land, which will not suffice for a Chazakah.)