Question: In light of the Gemara in Pesachim 'Gagin Lo Niskadshu', how can one eat Ma'aser Sheini on a tree?

Answer #1: The Mishnah is speaking about a tree that has few branches which are not four Tefachim wide and are therefore not Chashuv. Consequently, it is as if one is eating the Ma'aser in the air above the ground.

Answer #2: Alternatively, it is speaking even where the tree has many branches, but the air of Yerushalayim is like Yerushalayim (and has nothing to do with the Kedushah of the roofs of the Beis-ha'Mikdash).

Question: This is very difficult to understand. What prompts the Gemara to say that R. Yehudah is speaking Davka le'Chumra?

Answer: It is logical to minimize the Machlokes, and to say that R. Yehudah restricts his opinion to le'Chumra.

Clarification: We do not go after the branch 'Le'kula', to say that just as he is allowed to eat the Ma'aser beside the branch on the inside without redeeming it, so too, is he allowed to eat it beside the trunk on the outside without redeeming it; only le'Chumra, to forbid him to redeem it beside the trunk.

Implied Ruling: It does imply however, that it is obvious that one is permitted to eat the Ma'aser beside the branch. This is because, even though the tree goes after the branch le'Chumra, the branch does not go after the trunk le'Chumra.

Question: It is a little difficult to understand what prompts the Gemara to say that the Rabbanan argue with R. Yehudah in this point?

Answer: The fact that the Tana mentions the Arei Miklat together with Yerushalayim, suggests that they argue in both cases.

Explantion #1: Rav Ashi comes to answer what we asked 'Does that mean that if the trunk is inside and the branch outside, one may kill him'? And he answers that we go also after the branch wherever it is le'Chumra, such as where the trunk is outside and the branch inside, in which case one is not permitted to kill him even when he has only reached the trunk. And in the same manner we go after the trunk, to cast the branch after it le'Chumra - so that where the trunk is inside and the branch outside, one may not kill even when he has only reached the branch.

Question #1: In that case, just as the Tana says 'Halach Achar ha'Nof' (which Rav Ashi interpets as 'Af Achar ha'Nof'), he may just as well have said 'Halach Achar ha'Ikar'?

Question #2: Furhermore, above regarding Ma'aser, when the Gemara said that we go after the trunk le'Chumra, it implied that the Din of the branch itself was never Bateil to go after the trunk (as we explained there).

Explanation #2: Therefore the explanation of the Ram seems to be the correct one. The Ram explains that to be sure, the Din of the branch is never Bateil, even le'Chumra, as we just explained. And what R. Ashi therefore means is that we sometimes also cast the trunk after the branch le'Chumra, such as where the trunk is outside and the branch inside, where just as one cannot kill the Rotze'ach by the branch, so too, can one not kill him by the trunk. Sometimes however, the trunk goes after itself (it has its own Din) such as when it is inside, in which case one cannot kill the Rotze'ach, even though by the branch, which is outside, one may (as we explained above). In any event, when the trunk is inside he cannot kill him, since we only cast the trunk after the branch le'Chumra, but not le'Kula.

Rashi's Explanation: Rashi explains that the reason the Tana says 'Af Achar ha'Nof' is because, throughout Shas, we cast the branch after the trunk, and that is why here by Ir Miklat, he needs to inform us that sometimes we cast the trunk after the branch. That would also explain why the Tana opts to say 'Achar ha'Nof' rather than 'Achar ha'Ikar'.

Question: The Kashye remains however, that with regard to Ma'aser, we don't cast the branch after the trunk at all?

Conclusion: That explains why the Ram's explanation is correct.

Question #1: But have we not already said that he is exiled from one district to another?

Question #2: Furthermore, we have learned that a ben Levi goes into Galus from one town to another?

Answer: If he goes from one town to another, then he is permitted to traverse the entire town and all its borders; whereas if he goes to his own district, then his district gathers him in, forbidding him to go from one area to another.