Ma'asros, Chapter 5, Mishnah 5. Our Mishnah deals with produce that grows in the land of Suria - present-day Syria, which lies geographically to the north of Eretz Yisrael.
The status of Suria:
During the era of the First Beis HaMikdash, Suria was conquered by the armies of King David, but the conquest did not take place after all of Eretz Yisrael had been conquered; it was carried out, as it were, by his private troops. For that reason it does not have the status of Eretz Yisrael: politically it is part of Israel, but it does not carry the sanctity of Eretz Yisrael, and the mitzvos that depend on the land - among them Terumah and ma'asros - do not apply by Torah law to produce that grows there.
A parallel example in our times: the city of Eilat lies within the borders of the political entity called Israel and is under Jewish control, yet by Torah law its soil is not part of Eretz Yisrael, and the mitzvos that depend on the land do not apply there. Produce grown there does not require tithing by Torah law.
The rule in our case: produce from Suria is exempt from ma'asros by Torah law, but Jewish-owned produce from Suria is obligated in tithing by rabbinic law. Our Mishnah discusses a case in which the produce is not necessarily Jewish-owned, but rather the produce of a non-Jew.
Two possibilities regarding a non-Jew's produce:
The non-Jew owns the land and therefore also the produce growing on it, and he sells that produce - this is a non-Jew's produce, and it is certainly exempt.
The non-Jew owns the land, but a Jew bought the produce while it was still attached to the ground - here it is not clear whether it is considered a Jew's produce or a non-Jew's produce.
The Mishnah will address this distinction, at least according to one of the opinions it presents.
The case of the Mishnah:
A Jew buys a vegetable field from a non-Jew in Suria while the vegetables are still attached to the ground. In the first part of the Mishnah, the Jew buys the land itself along with the vegetables growing in it. The question is: are those vegetables obligated in ma'asros if at the time of the purchase they had already passed the stage of onas hama'asros?
The opinion of the Tanna Kamma:
"Kanah kodem shebau l'onas hama'asros" - the small carrots growing in the field had not yet reached the stage of onas hama'asros, and the field became a Jew's field. Once the carrots grew and reached onas hama'asros, they were already under Jewish ownership at the moment they crossed this significant threshold, and therefore this is Jewish produce in Suria - and it is obligated in Terumah and ma'asros by rabbinic law.
"Kanah mishebau l'onas hama'asros" - the cutoff point at which the obligation to separate takes effect occurred while the field was still under non-Jewish ownership. Therefore, whether he bought only the carrots after this stage or bought the land together with the carrots in it, they are exempt from the separation requirements, since they were in truth under non-Jewish ownership and outside of Eretz Yisrael.
The Mishnah therefore continues: "V'lokeit k'darko v'holeich" - he may harvest in his usual manner, and there is no obligation to tithe.
The Dispute Between the Tanna Kamma and Rabbi Yehudah:
According to the Tanna Kamma, the leniency applies only to the owner of the field himself, while Rabbi Yehudah says that his workers too may harvest the carrots or any other vegetable that grew, and there is no problem with that. According to the Tanna Kamma, if a person hired a third party to harvest the vegetables that he acquired when he purchased the field after the season of tithes, the Sages were concerned that onlookers would assume that this produce really is obligated in tithes.
A distinguishing sign is therefore required, so that people will understand that this field is unusual: it was purchased by a Jew in a year in which the season of tithes had already passed, and for that reason its status is unique. The distinction is drawn between harvesting done by the owner himself and harvesting done by a third party. Rabbi Yehudah holds that no distinguishing sign is necessary, and the Tanna Kamma holds that it is: if he harvested himself - those carrots that he purchased from the non-Jew in Syria after the season of tithes are exempt; but if he brought someone else to harvest, they are obligated in tithes by rabbinic law.
The View of Rabban Shimon ben Gamliel:
Rabban Shimon ben Gamliel distinguishes between purchasing the land together with the vegetables growing in it and purchasing the vegetables alone. In his view, if he bought only the vegetables and the land remained the land of a non-Jew in Syria, the entire discussion never begins: this is the produce of a non-Jew. When a Jew buys vegetables from a non-Jew while they are still attached to the ground, they are completely exempt from tithes, and it makes no difference whether he bought them before the season of tithes or after it, for even if he bought them earlier, these carrots are growing in the field of a non-Jew and not in Eretz Yisrael.
All of this applies only when he bought the land itself, and in that case Rabban Shimon ben Gamliel agrees: if at the time he purchased the land the carrots had already passed the season of tithes - he is exempt, and if he bought it before that - he is obligated. These are the words of the Mishnah: "Amar Rabban Shimon ben Gamliel: bameh devarim amurim? Bizman shekanah karka" - that is, what we said, that carrots purchased from a non-Jew in Syria in the middle of their growth are obligated in tithes if they were purchased before the season of tithes, applies only when he bought not merely the carrots but the land itself, thereby making it a Jew's field in Syria.
"Aval bizman shelo kanah karka" - if he did not buy the land but only the small carrots that were beginning to grow, he is exempt. Even if he bought them before they reached the season of tithes, so that when they crossed that critical threshold he was already their owner and he is a Jew - what of it? He owns them in Syria, and moreover, the land in which they are growing is not his but a non-Jew's. Therefore everything is exempt.
The View of Rebbi - "Af Lefi Cheshbon":
The last section of the Mishnah can be confusing, because Rebbi disagrees - but not with Rabban Shimon ben Gamliel. He disagrees with the first section of the Mishnah, which stated that produce purchased after the season of tithes is exempt. Rebbi says: "Af lefi cheshbon" - everything goes according to the proportion.
How so? Let us assume for the sake of the discussion that carrots which have reached a third of their growth are considered to have reached the season of tithes. If he bought the carrots when they were about half grown, they had already passed the season of tithes, and at that critical moment the non-Jew was their owner. The Tanna Kamma holds that they are permanently exempt from tithes, while Rebbi says that this is not necessarily so: it is true that as long as they grew in the hands of the non-Jew they were exempt because they belonged to a non-Jew, but now they are owned by a Jew, and the growth that takes place while the Jew owns them is obligated in tithes.
He must therefore make a calculation and determine the proportion: if half of the carrot grew while it was in his ownership and he is a Jew, he will have to tithe fifty percent of the total volume that came out of the ground, since at the very least, proportionally, half of every carrot grew after it came into his possession, and that half is subject to the obligations of tithes. This is the view of Rebbi, and the halachah does not follow him.
The halachah:
The halachah follows Rabban Shimon ben Gamliel: produce from Syria is tithed only if a Jew owns the land, and even then only if he bought it before the season of tithing. If a non-Jew owns the land in Syria, it makes no difference when the Jew bought the carrots growing in it - they are exempt from the obligations of tithing.
The Vilna Gaon rules like Rabbi Yehudah, unlike the Rambam and the Bartenura, who did not write this way: in a case where he bought the produce while it was still attached to the ground after the season of tithing, and he also bought the land itself after the season of tithing, not only he but even his workers may work the land and harvest the vegetables, and there is no problem with this, and there is no obligation to tithe them in such a scenario.