Gemara

(Beraisa - R. Yoshiyah): "Li'Shmos Matos Avosam Yinchalu" teaches that portions of Eretz Yisrael were allocated to those who left Mitzrayim;

R. Yonason says, portions of Eretz Yisrael were allocated to those who entered - "la'Eleh Techalek ha'Aretz b'Nachalah";

Question: Perhaps "li'Shmos Matos Avosam Yinchalu" does not refer to those who left Mitzrayim, rather, to the 12 tribes!

Answer: "V'Nosati Osah Lachem Morashah" was said to those who left Mitzrayim.

119b: Moshe was unsure whether Bnei Yisrael already owned Eretz Yisrael before entering. It says "v'Nosati Osah Lachem Morasha." Is it also an inheritance (and a Bechor gets double)? Or, does this teach only that the parents bequeath but do not inherit? Hash-m told him that it is also an inheritance.

Kidushin 36b (Mishnah): Any Mitzvah that depends on the land applies only in Eretz Yisrael, except for Orlah (the Isur to eat fruits of the first three years of a tree) and Kilayim (diverse seeds planted together).

38b (Mishnah): Safek Orlah in Eretz Yisrael is forbidden. In Surya (lands that David conquered and annexed to Yisrael) it is permitted (if it was already picked). In Chutz La'aretz, one may even ask the seller to pick (from an field with Orlah and permitted trees), as long as he doesn't see him pick Orlah.

Mishnah (Orlah 1:2): When our ancestors came to Eretz Yisrael, what they found planted was exempt. Orlah applies to what grows by itself, and to what a Nochri or robber planted.

Yevamos 122a (Beraisa): If a Nochri was selling fruit and said 'it is Orlah', his words have no effect, since he intended only to praise his fruit.

Avodah Zarah 35b (Rav Nachman bar Yitzchak): Cheese of Nochrim is forbidden because they use sap of Orlah to curdle.

Question: If so, it should be forbidden to benefit from their cheese!

This is left difficult.

Rishonim

Rambam (Hilchos Ma'aser Sheni 10:5): What grows by itself, and what a Nochri planted, whether for a Yisrael or for himself, Orlah and Revai (fourth-year produce, which gets Kedushas Ma'aser Sheni) apply to the Peros.

Kesef Mishneh: The Rambam retracted from what he wrote in Perush ha'Mishnayos, due to the many proofs that Orlah applies even to what a Nochri planted for himself.

Tziyunim (in Frankel Rambam): Teshuvas ha'Rambam, and a Kesav Yad of Perush ha'Mishnayos are like it says in the Mishnah Torah.

Perush ha'Mishnayos (Orlah 1:2): Orlah applies to what a Nochri planted for a Yisrael employer, or for free if he wanted to toil for a Yisrael. However, if a Nochri planted for himself, and then a Yisrael bought it, it is exempt.

Rosh (Kidushin 1:62): The Yerushalmi says that the Mishnah omits Chalah, for it teaches only what applies even to Nochrim. R. Tam derived from here that Orlah, Kilai ha'Kerem (diverse seeds planted with grapes) and Revai apply to Peros Nochrim. We also learn from a Nochri who said 'my Peros are Orlah.' He is not believed, for he intended only to praise his Peros. This is not only when he bought Peros from a Yisrael, for in the Seifa, Rebbi says 'if he says that he bought them from Ploni, he is believed.' This implies that the Reisha discusses the Nochri's own Peros. Also the Mishnah (Orlah 1:2) obligates a Nochri's Peros. The Tosefta says that if a Nochri grafted, we count from when it was planted. R. Peter brings a proof from a Tosefta, which says that Orlah and Kilai ha'Kerem apply equally to Nochrim, in Eretz Yisrael and Surya and Chutz la'Aretz. R. Yehudah and Chachamim argue about whether Kerem Revai applies to a Nochri in Surya (i.e. but all agree that Orlah applies.) Also, our Sugya says that in Chutz La'aretz, one may even ask the seller to pick, as long as he doesn't see him pick Orlah. This cannot discuss a Yisrael seller, for just like one may not eat Orlah, he may not sell it, for one may not benefit from it. Another proof is from cheese of Nochrim. It is forbidden because they use sap of Orlah to curdle. The Gemara connotes that it is forbidden everywhere, even where Yisre'elim do not live. If so, why may we drink wine? Every year, (Nochrim) are Mavrich (insert the vines back into the ground). After it takes root, they cut the middle (above the ground), making two vines. This is considered Orlah (Rosh Hashanah 9b)! We can answer like it says in Sotah (43b), that R. Eliezer ben Yakov holds that one who was Mavrich does not return from war, for it is not called "planted a vineyard." Likewise, we can say that he holds that Orlah applies to what "you will plant", but not to wat you will be Mavrich. However, even R. Eliezer holds that Mavrich is (when the inserted end comes out from the ground elsewhere, but) not when the vine is cut in the middle and one end is separated from the initial root (this is like planting)! I answer based on the Mishnah (Orlah 1:5) which says that if Havrachah was done every year, we count Orlah from when it was cut. If vines were grafted one onto another, even if Havrachah was done, it is permitted. R. Shimshon explains that farmers dig a hole and bend a branch into the hole and cover it. It comes out elsewhere, but remains attached to the initial tree. Each year, they similarly Mavrich from the new tree. Orlah does not apply to, for all are attached to the old tree. If they are cut from the old tree, it is as if all the grafted trees were planted now, and we count Orlah from when they were cut. The Gemara that says that Orlah applies to Havrachah, i.e. after they were cut from the old tree. According to R. Eliezer, Orlah in Chutz la'Aretz is only when one plants a new tree. In Chutz la'Aretz we follow the most lenient opinion in Eretz Yisrael. Tosfos permits because it is a Safek, which is permitted in Chutz la'Aretz.

Tosfos (36b DH Kol): R. Shimshon asked farmers, and they said that they do not cut off the new trees from the old tree. This can be seen, for then the new shoots face away. If they were cut, they face the old tree.

Ran (Kidushin 15a DH Masnisin): Another proof that Orlah applies to Peros Nochrim is from the Mishnah, which says that Mishnah when our ancestors came to Eretz Yisrael, what they found planted was exempt. The Yerushalmi exempts what Nochrim planted before Yisrael entered Eretz Yisrael, but not what they planted after Yisrael entered. Orlah applies to what grows by itself, and to what a Nochri planted.

Mordechai (Kidushin 501): We must say that Nochrim used to curdle cheese with Vadai Orlah, for Safek Orlah is permitted in Chutz la'Aretz. Why may we drink wine of Nochrim? Do not say that most vines are not Orlah, for from one head (inserted into the ground) four or five come out! If they do not cut it off from the initial tree, there is no Isur.

Question (asked to Rashba): R. Shimshon forbids Orlah of Nochrim. If so, why is there no Mishnah teaching this? The Yerushalmi (that obligates of Nochrim) discusses a Nochri who planted in a Yisrael's field, similar to the case of a thief. Surely the case of Kilayim (that it forbids) is when a Nochri planted in a Yisrael's field, for in his own field, it is permitted. Even Kilayim of a Yisrael is forbidden only due to intent, e.g. if he despaired of fixing the breached fence. Will a Nochri forbid his own Kilayim?!

Answer (Rashba 5:56): R. Shimshon is correct. The Gemara must discuss buying Safek Orlah and Kilayim from a Nochri, for Yisre'elim are not suspected about these. It is difficult to say that a Yisrael is suspected because he is outside the field. It is unreasonable to say that the Nochri stole from a Yisrael's field and sells right next to it. This is not common at all. Surely Orlah 1:2 discusses a Nochri who planted in his own field. If it were in a Yisrael's field, this is of Yisrael! What was planted before Bnei Yisrael entered Eretz Yisrael was exempt. This is because Eretz Yisrael was Muchzak to belong to Bnei Yisrael, like it says in Bava Basra, that it was an inheritance from the Avos. This is why we needed a verse to exempt what was planted beforehand. The Yerushalmi says that "every food tree" includes a Nochri who planted in his own. A thief is one who stole and planted for himself. The Yerushalmi asked that one cannot steal land! It answered that even so, one can despair from land. Rav Nachman said that cheese of Nochrim is forbidden because they use sap of Orlah to curdle. He must hold that Chachamim were not stringent to forbid benefit from it, for it is not Vadai that they use Orlah. Even if you will say that Rav Nachman erred about why their cheese is forbidden, he forbids Orlah of Nochrim, and we do not know anyone who permits. Why should we say that he erred also about this?! Do not say that the only Chiyuv Orlah of Peros Nochri is when he planted in a Yisrael's field, for if so the exemption of Chalah is when a Nochri kneaded a Yisrael's dough. We never find that Digun (final processing) of a Nochri exempts a Yisrael's grain (and similarly regarding Chalah)! It is exempt only if a Nochri owned it at the time of final processing.

Rashba (4:100): In many cases Chachamim were stringent about Nochrim to consider a Safek Isur like a Vadai Isur.

Poskim

Shulchan Aruch (YD 294:8): Orlah applies everywhere, at all times, both to produce of Yisre'elim and of Nochrim. However, in Eretz Yisrael it is mid'Oraisa, and in Chutz la'Aretz it is a tradition from Sinai.

Pischei Teshuvah (7): The Chasam Sofer (YD 286 DH Ach) leans to say that Orlah of Nochrim in Chutz la'Aretz is only mid'Rabanan.