1) BRINGING "BIKURIM" FROM FRUITS OF CHUTZ LA'ARETZ
QUESTION: The Gemara explains that the verse, "Asher Tavo me'Artzecha" (Devarim 26:2), teaches that one does not bring Bikurim from fruit grown in Chutz la'Aretz.
Why does the Gemara need to derive from a verse that the Mitzvah of Bikurim does not apply to fruit grown in Chutz la'Aretz? Bikurim should be no different from all of the other "Mitzvos ha'Teluyos ba'Aretz," such as Terumos and Ma'aseros, which apply only to fruit that grows in Eretz Yisrael (as the Gemara in Kidushin 37a teaches)!
ANSWER: TOSFOS here (DH ha'Hu, in his second approach) answers in the name of RASHBA (the Rash mi'Shantz) that the Mitzvah of Bikurim is an obligation on the person who owns the fruit to bring it to the Mizbe'ach. The Mitzvah is not on the object, the produce of Eretz Yisrael, which requires that a certain act be done with the produce before it is permitted to be eaten. He proves this from the fact that the rest of the fruit in the field is not prohibited from being eaten (like Tevel) before Bikurim are separated, and from the fact that Bikurim can be separated even before the fruit is picked, while it is still attached to the ground (and not yet considered "produce").
This approach answers another question. The Mishnah in Kelim (1:6) states that Eretz Yisrael has more Kedushah than all other lands. "In what way is it holier," the Mishnah asks, "because we bring from there the Korban ha'Omer, Bikurim, and Shtei ha'Lechem" which cannot be brought from any land outside of Eretz Yisrael.
Why does the Mishnah not mention that Eretz Yisrael is also holier because of the obligation to separate Terumos and Ma'aseros from produce that grows in Eretz Yisrael? (See Insights to Nedarim 22:1.)
According to Rashba cited by Tosfos, the reason why the Mishnah does not mention the other "Mitzvos ha'Teluyos ba'Aretz" is that those Mitzvos are not an indication of the Kedushah of the land; rather, they are obligations that are incumbent upon the produce of Eretz Yisrael. That is, although the Torah forbids the eating of fruit grown in Eretz Yisrael before Terumos and Ma'aseros have been separated, the fact that Terumos and Ma'aseros must be separated is not a manifestation of the Kedushah of the land. The reason why the Mishnah lists the Korban ha'Omer and Shtei ha'Lechem is that the fact that these items may be brought to the Beis ha'Mikdash only if they grew in Eretz Yisrael demonstrates the Kedushah of Eretz Yisrael. The Mitzvah of Bikurim, too, is practiced in Eretz Yisrael not because it is a "Mitzvah ha'Teluyah ba'Aretz," but rather because of the Kedushah of Eretz Yisrael. (See also Insights to Kidushin 37:1. This approach also answers the question of the VILNA GA'ON in ELIYAH RABAH there in Kelim.)
2) BRINGING "BIKURIM" WITHOUT READING THE "PARSHAH OF BIKURIM"
QUESTION: According to the Chachamim, one who buys two trees in the field of his neighbor brings Bikurim but does not read the Parshah of Bikurim ("Mevi v'Eino Korei"). The RASHBAM explains that he does not read the Parshah of Bikurim because he did not acquire the land beneath the trees, and therefore the verse in the Parshah of Bikurim which says, "Asher Nasata Li" -- "And now I have brought the first of the fruits of the land which You, Hash-m, have given to me" (Devarim 26:10), does not apply to these fruits, since they did not grow on a tree that was planted on land owned by the owner of the fruit.
Later (beginning of 81b, DH Mai Taima), when the Rashbam explains why, according to Rebbi Meir, a person is Mevi v'Eino Korei when he owns one tree (and, according to the Chachamim, a person is Mevi v'Eino Korei when he owns two trees), the Rashbam writes that he cannot read the Parshah of Bikurim because the verse says "Asher Tavi me'Artzecha" -- "And you shall take of the first of all the fruit of the earth, which you shall bring from your land that Hash-m gives you" (Devarim 26:2). The Bikurim must be brought from the land owned by the owner of the fruit. As the Rashbam explains, the Gemara then asks that since the owner of a single tree does not own the land beneath it, just as he cannot read the Parshah of Bikurim he also should not have to bring Bikurim altogether, because this verse implies that one who does not own the land beneath the tree does not even bring Bikurim. The Gemara answers that there is a Safek whether one who buys one tree (or two trees according to the Chachamim) owns the land beneath it or not, and therefore out of doubt he must conduct himself stringently and bring Bikurim without reading the Parshah.
Why does the Rashbam there cite a different verse there (81b) from the one he cites here (81a) to explain that one who buys two trees according to the Chachamim is Mevi v'Eino Korei? (RASHASH)
ANSWER: The Rashbam may understand the Gemara the way the TOSFOS RID explains earlier (27a). The Tosfos Rid explains that the requirements for bringing Bikurim differ from the requirements for reading the Parshah of Bikurim. Although a person cannot read the Parshah of Bikurim unless he actually owns the land beneath the tree, nevertheless he can bring Bikurim even though he does not own the land, since he has permission to keep his tree there. The reason for this is that the verses that discuss bringing Bikurim ("Artzecha" in Devarim 26:2, and "Admascha" in Shemos 23:19) exclude only fruit brought from trees planted on land that he has no permission to use (see Sukah 9a). The verse that discusses reading the Parshah of Bikurim says "ha'Adamah Asher Nasata Li" (Devarim 26:10), which implies that the land was actually given to him and he owns it. (See Insights to Bava Basra 27:1:b.)
The Tosfos Rid derives this from the words of Reish Lakish later in Bava Basra (136a) as well as from the reply of Rebbi Elazar in the Gemara here. When Rebbi Elazar was asked why a person must bring Bikurim when he owns two trees even though he does not read the Parshah, Rebbi Elazar replied that the "early authorities did not tell the reason, and you are asking me to teach it in the Beis Midrash!" This implies that there is a reason to distinguish between bringing Bikurim and reading the Parshah of Bikurim, but Rebbi Elazar did not want to teach it publicly in the Beis Midrash. Even though Rabah explained that the Chachamim were uncertain about whether a person acquires the land beneath one tree and that is why one does not read the Parshah of Bikurim, Rebbi Elazar had a different explanation. His explanation was, as explained above, that the obligation to bring Bikurim is not comparable to the obligation to read the Parshah of Bikurim.
This also seems to be the opinion of the Rashbam later (136b, DH Mevi v'Eino Korei), who writes clearly that one does not need to own the land beneath the tree in order to bring Bikurim, but he does need to own the land in order to read the Parshah of Bikurim.
The Rashbam later (81b) is explaining the opinion of those who asked Rebbi Elazar why there should be a difference between bringing Bikurim and reading the Parshah of Bikurim. They followed the view of Rabah, who maintains that the two are indistinguishable. Therefore, the Rashbam explains that they learn from "Artzecha" (Devarim 26:2) that one cannot even bring Bikurim if he does not actually own the land beneath the tree. Here (81a), however, the Rashbam is explaining the Mishnah according to the Halachic view, which is that of Rebbi Elazar, who maintains that only the verse of "ha'Adamah Asher Nasata Li," which pertains to reading the Parshah, requires that the person own the land beneath the tree, but in order to bring Bikurim one need not own the land.
3) BRINGING "BIKURIM" OUT OF DOUBT
QUESTION: The Gemara explains that in the case of a person who buys two trees in his neighbor's field, there is a doubt about whether he acquires the land beneath the trees or not. As a result of this doubt, he must bring Bikurim but he does not recite the Parshah of Bikurim ("Mevi v'Eino Korei").
The Mishnah, however, teaches that with regard to monetary law, the rule is that the buyer does not have rights to the land beneath the trees because of the principle of "ha'Motzi me'Chaveiro Alav ha'Re'ayah." Because of the doubt, the seller is deemed to own the land such that he may use the land beneath the trees for his own purposes, such as to be Mekadesh a woman or to buy an Esrog. If the land beneath the trees is deemed to belong to the seller because of "ha'Motzi me'Chaveiro Alav ha'Re'ayah," then why does the buyer need to bring Bikurim because of the Safek? Once the rule of "ha'Motzi me'Chaveiro" is applied, the land is not the buyer's and he should not be obligated to bring Bikurim even out of doubt! (SHA'AREI YOSHER 5:6, KOVETZ SHI'URIM to Bava Basra #97)
ANSWER: RAV ELCHANAN WASSERMAN Hy'd in KOVETZ HE'OROS (#71) explains that the principle of "ha'Motzi me'Chaveiro Alav ha'Re'ayah" does not entitle a person to the rights to an object that might not be his. Applying the principle of "ha'Motzi me'Chaveiro Alav ha'Re'ayah" does not cause the ownership of the object to change. Rather, "ha'Motzi me'Chaveiro Alav ha'Re'ayah" gives the person the rights to use the object and to act as though it belongs to him (such that he may be Mekadesh a woman with it, or buy an Esrog with it). The law of Bikurim, however, depends on whether the land actually belongs to the person or not, and that remains a doubt.
What is the difference between the case of Bikurim, and the cases of Kidushin and buying an Esrog? The Sha'arei Yosher (5:8) and Kovetz Shi'urim (#97) explain that there are two distinct definitions of ownership: the first is that the person has title to an object because he purchased it or acquired it in some other way; the second is that the person is given full rights of usage of the object according to monetary law, from a Halachic point of view. With regard to most Isurim (such as Kidushin and Esrog), the definition of ownership depends on whether he owns it with regard to its usage for monetary matters ("Mamonos"). If the object is considered his by monetary law, then it is then his for Kidushin and Esrog as well. With regard to Bikurim, however, the definition of ownership does not depend on his rights of usage with regard to "Mamonos" but on having actual title to the property.
The Sha'arei Yosher explains the reason for this difference. His intention might be as follows. When a person uses an object to create Kidushin or for the Mitzvah of Esrog, he actually uses the object of doubtful ownership for the Mitzvah. In contrast, in the case of Bikurim, the person who has doubtful ownership of the land does not use the land for any Mitzvah at all. Rather, ownership of the land is a precondition for the Mitzvah; the land must belong to the owner of the fruit in order for him to be obligated to bring the fruit (which is certainly his) as Bikurim and read Parshas Bikurim. When the Torah requires ownership of an object that is not being used for the Mitzvah as a precondition for performing a Mitzvah, it is assumed that the Torah requires that he have the actual title to the object and not merely that he have rights of usage.
The Sha'arei Yosher adds that if the owner of the land purchases the fruit from the owner of the trees, he probably would be required to bring Bikurim and read the Parshah of Bikurim -- at least according to those who maintain that a Kinyan Peros (the right of usage) is like Kinyan ha'Guf with regard to Bikurim (see Bava Basra 136a). Since he has unquestionable rights to the use of the land, the land is considered his as far as Bikurim is concerned even if he is not the "true" owner of the land.
(This approach is debatable if one suggests that there is a difference between one who has the rights of usage because he purchased those rights (as in the case of Kinyan Peros) and one who has rights of usage out of doubt, as in the case of the Gemara here. Perhaps one who uses the property out of doubt is still not the "owner" of the rights of usage, but simply the default user of the object. Consequently, the object (the land, in this case) cannot be called "his.")