1) HARVESTING THREE CROPS IN A SINGLE YEAR
QUESTION: The Mishnah teaches that the Chazakah of a "Beis ha'Shalchin" is a full three years ("Shalosh Shanim mi'Yom l'Yom"), as opposed to the Chazakah of a "Beis ha'Ba'al." RASHI teaches that since a Beis ha'Shalchin has its own water source, it produces fruits constantly throughout the year, and not just one crop during one part of the year. Therefore, in order to make a Chazakah on the field, the Machzik must occupy and use the field for three full years.
The Gemara (end of 28b) teaches that according to Rebbi Yishmael, a person can make a Chazakah by reaping three crops in a single year, such as by planting and harvesting Aspasta in one month, and repeating that for the next two months. If a Beis ha'Shalchin constantly produces crops one after the other, then Rebbi Yishmael should rule that a person can make a Chazakah on a Beis ha'Shalchin in one year or less! What is the difference between a Beis ha'Shalchin and Aspasta? (RASHBA)
ANSWERS:
(a) The RASHBA (28b) and ALIYOS D'RABEINU YONAH answer that since the Beis ha'Shalchin constantly produces fruit without interruption, an entire year's harvest is usually taken by the same person and it is not divided up into small sections. Therefore, a Chazakah can be made only by using the field for the entire year, and the year's produce is all considered to be one large crop.
The RASHBA questions this, however, from the Gemara (28b) which says that harvesting the three different parts of the Tzelaf, or harvesting three figs in three days, would be considered a Chazakah if not for the fact that the fruit which is harvested later already exists in a premature, underdeveloped form at the time that the first crop is harvested. Since the fruit planted at the end of the year in a Beis ha'Shalchin was obviously not in existence at all at the beginning of the year when the previous crop was harvested, why should it not be considered a separate crop with regard to Chazakah?
Perhaps the answer is that when the Gemara says that the figs which were harvested later were already there during the first harvest but were not yet mature, it does not mean that the last fig was on the tree at the time that the first fig was harvested. Rather, the Gemara means that the last fig is considered an extension of the crop which bore the first fig, since there was no harvest between them to divide the crop into two. Accordingly, the Gemara itself expresses the logic of the Rashba. (M. KORNFELD)
(b) The GILYON TOSFOS cited by the Shitah Mekubetzes explains that the Beis ha'Shalchin does not produce more than one crop of fruit during one season. However, the field is worked throughout the year, and that is why the Chazakah is a full three years, mi'Yom l'Yom.

28b----------------------------------------28b

2) HALACHAH: DERIVING THE LAWS OF "CHAZAKAH" FROM "SHOR HA'MU'AD"
QUESTION: The Gemara suggests that the source for the Halachah of "Chezkas Shalom Shanim," the Chazakah of three years, is the Halachah of Shor ha'Mu'ad. Just as an ox becomes a Mu'ad only after it gores on three separate days, so, too, a person's use of a field proves that he is the owner of the field only when he has used the field for three years. The Gemara asks why three years are necessary to make a Chazakah according to Rebbi Meir, who says that a Shor becomes a Shor ha'Mu'ad even by goring three times on one day. Rebbi Meir maintains that if three gorings on three separate days prove that the Shor is a Mu'ad, then all the more so three gorings on a single day prove that it is accustomed to goring and that it must be a Mu'ad. The Gemara says that, indeed, according to Rebbi Meir if one collects three separate harvests of fruit in the same year he will have a Chazakah.
The Poskim (OC 114:9) derive from Rebbi Meir's ruling a practical Halachah with regard to the laws of Shemoneh Esreh. When a person is in doubt about whether he said "Morid ha'Geshem" in the summertime (when he was not supposed to say it), he must assume that his tongue said what it was accustomed to saying (which until now was "Morid ha'Geshem"), and thus he must repeat the Shemoneh Esreh. This Halachah applies during the first thirty days after the beginning of Pesach, when his tongue is still accustomed to saying "Morid ha'Geshem." The MAHARAM MI'ROTENBURG proposes that there is a way to accustom one's tongue to saying the appropriate words even before thirty days have passed. By repeating the appropriate phrase of Shemoneh Esreh ninety times, his tongue will become accustomed to saying that phrase based on the logic of Rebbi Meir -- events that occur in proximity affect a person's habits more than events that are separated by time.
How can the Maharam base his ruling on Rebbi Meir's teaching? The Halachah follows the view of Rebbi Yehudah, who maintains that a Shor becomes a Mu'ad only when it gores on three separate days. This implies that events that occur in close proximity do not habituate a person more than events that do not occur with such proximity. (DERISHAH, MAGEN AVRAHAM in the name of the SHELAH, TAZ)
ANSWERS:
(a) The MAGEN AVRAHAM suggests that Rebbi Yehudah argues with Rebbi Meir only because of a verse that seems to refute Rebbi Meir's view. The verse (Vayikra 15:25) teaches that a woman becomes a Zavah after she sees blood on three consecutive days, but not after she sees blood three times on one day. This verse seems to refute Rebbi Meir's view. Perhaps with regard to Shemoneh Esreh, however, that Gezeiras ha'Kasuv will not apply.
However, the Magen Avraham rejects this approach. If Rebbi Yehudah derives the Halachos of Shor ha'Mu'ad from Zavah, then why should he not learn all of the Halachos from Zavah?
The DERISHAH and NODA B'YEHUDAH (OC 1:26) answer that Rebbi Yehudah applies the principle learned from Zavah (i.e. that three events are needed to establish the new status) only where an Isur or Tum'ah is involved. The laws of Shemoneh Esreh involve no Isur or Tum'ah, but rather a question of what a person has become accustomed to saying, and it is not derived from a Halachah related to Isur or Tum'ah.
Why, then, does the Gemara say that a Chazakah should work if a person makes three harvests in one year, according to Rebbi Meir? The same should be true according to Rebbi Yehudah, since this Chazakah is not based on a verse but on the nature of a person! The Derishah writes that the Gemara mentions Rebbi Meir only because he is the one who states explicitly that events that are close in proximity have more of an effect than events that take place at larger internals of time. The Halachah, however, should be true according to Rebbi Yehudah as well since he agrees with Rebbi Meir on this point. (This might explain why the Gemara rejects Shor ha'Mu'ad as the source for "Chezkas Shalosh Shanim" according to the Chachamim who argue with Rebbi Yishmael and say that three harvests in one year do not constitute a Chazakah. Why does the Gemara not say that the Chachamim follow the view of Rebbi Yehudah, and Rebbi Yishmael follows the view of Rebbi Meir? According to the Derishah, Rebbi Meir and Rebbi Yehudah do not argue on this point, and therefore a new source must be found for "Chezkas Shalosh Shanim" according to the Chachamim.)
However, the Derishah and Magen Avraham question this approach from a Beraisa in Ta'anis (21b) that says that if three people die in three days in a small city, it is considered a dangerous plague, and the residents of the city must fast. The Gemara relates that an Amora decreed a day of fasting when three people died on one day. Rav Nachman bar Yitzchak said that this Amora followed the view of Rebbi Meir, who says that events that take place at smaller intervals have more of an effect. If Rebbi Yehudah argues with Rebbi Meir only with regard to a law derived from a verse, then he should agree with this Halachah. It is possible that the Gemara merely quotes Rebbi Meir because he is the one who stated this principle explicitly, but Rebbi Yehudah indeed agrees with it in this case. However, the RAMBAM (Hilchos Ta'aniyos 2:5) and the SHULCHAN ARUCH (OC 576:2) rule that a Ta'anis is not proclaimed if three people die on one day, because the Halachah follows Rebbi Yehudah. (See Derishah.)
(b) The MAGEN AVRAHAM suggests that Rebbi Yehudah disagrees with Rebbi Meir only in the cases of a Shor ha'Mu'ad and a Zavah since other factors might be involved, aside from the factor of becoming accustomed to a certain type of action. A Zavah might see Dam because of illness, and a Shor ha'Mu'ad might gore because it was in a bad mood that day. The same reasoning applies to the case of a plague in a city, where other factors, such as the weather on that day, might have affected people's health. In such cases, the principle of Rebbi Meir would not apply. However, with regard to saying "Morid ha'Geshem," which a person's mouth says by rote when he is not concentrating, and which would not be influenced by other factors, Rebbi Yehudah would agree with Rebbi Meir's principle.
The VILNA GA'ON, however, does not accept the ruling of the Maharam because of the question of the Magen Avraham. The TUR cites RABEINU PERETZ who disagrees with the Maharam for a different reason: even if we accept Rebbi Meir's principle, it might not apply to accustoming one's tongue to pray in a certain way, since time is an important factor and has more of an effect on accustoming a person to say something by rote.

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