(Mishnah): There are three laws of Asheiros forbidden due to idolatry:

If a tree was originally planted to be worshipped, it is forbidden;

If one cut it (leaving the stump) or the branches in order to worship the new growth, if the new growth is removed, the tree is permitted;

If idolatry was put under it and removed it, the tree is permitted.

(Gemara - d'Vei R. Yanai): (The tree is forbidden) only if he was Markiv (put shoots into the ground for new growth) or grafted onto it.

Objection: The Mishnah forbids if he cut it or the branches!

Correction: Rather, d'Vei R. Yanai taught that even if he was Markiv or grafted onto it, when the new growth is removed, the tree is permitted.

One might have thought that since he was Markiv or grafted onto the tree itself, it is as if the tree was originally planted for idolatry, and the entire tree is forbidden. He teaches that this is not so.

(Shmuel): If one bows to a tree, the future growth is forbidden.

Question (R. Elazar - Mishnah): If one cut it or the branches, if the new growth is removed, the tree is permitted;

Future growth is forbidden if he cut it or the branches, but not if he only worshipped it!

Answer #1 (on behalf of Shmuel): The Mishnah is like Chachamim. My law is according to R. Yosi b'Rebbi Yehudah, who forbids a tree that was planted and later worshipped.

Objection (Rav Ashi): Why must we say that Chachamim and R. Yosi b'Rebbi Yehudah argue about whether future growth is forbidden, and Shmuel's law is like R. Yosi b'Rebbi Yehudah?

Perhaps all forbid future growth, and they argue about whether the previous growth is forbidden (and Shmuel's law is like everyone)!

R. Yosi b'Rebbi Yehudah learns that the previous growth is forbidden from "va'Ashereihem Tisrefun ba'Esh";

Chachamim learn that previous growth is forbidden from "va'Ashereihem Tigade'un";

The verse discusses a tree whose stump is permitted but the growth is forbidden, i.e. it was planted and later worshipped.

Question: Above, we explained just the contrary (each learns from the other verse)!

Answer: Indeed, we can explain similarly to above after switching the opinions. (The Beraisa did not say how each expounded.)

Question: If so, who taught our Mishnah, which says that future growth is forbidden only if he cut it or the branches?

According to Chachamim, it is forbidden even if he did not cut anything;

According to R. Yosi b'Rebbi Yehudah, if he cut it or the branches, even the initial growth is forbidden!

Answer #1: The Mishnah is like R. Yosi b'Rebbi Yehudah. He forbids the entire tree only when it was worshipped normally;

If he cut it or the branches, he shows that he wants to worship only future growth, so the initial growth is permitted!

Answer #2: The Mishnah is like Chachamim. They teach about cutting it or the branches, for this is a Chidush;

One might have thought that since he did an action to the tree itself, the entire tree is forbidden. The Mishnah teaches that this is not so.

(Mishnah) Question: What is an Asherah?

Answer #1: It is a tree with idolatry under it;

Answer #2 (R. Shimon): It is a tree that is worshipped.

A case occurred in which people worshipped a tree, and there was a pile underneath it. R. Shimon commanded to search the pile. They did, and they found an image.

R. Shimon: They were worshipping the image. The tree is permitted.

(Gemara) Question: Why does the Mishnah ask 'What is an Asherah?'? The previous Mishnah taught this (and it gave three examples, not just one)!

Answer: Our Mishnah means, of the three Asheiros, all agree that two are forbidden. R. Shimon and Chachamim argue about one of them;

What is the Asherah that they argue about? Chachamim forbid even a tree with idolatry under it. R. Shimon forbids only a tree that is worshipped.

(New) question: If we do not know about a tree, how do we know whether it is an Asherah?

Answer #1 (Rav): If the priests (of idolatry) sit under it and do not eat its fruits, it is an Asherah.

Answer #2 (Shmuel): Even if they say 'the fruits are for Bei Nitzrefei (an idol)', the tree is forbidden, for they make beer from the fruits and drink it on their festival.

(Ameimar): The Halachah follows Shmuel.

(Mishnah): One may not sit in its shade. If he sat, he is Tahor;

One may not pass under it. If he did, he is Tamei;

If its foliage was overhanging a Reshus ha'Rabim and he passed under it, he is Tahor.

(Gemara) Version #1 - Question: Obviously, he may not sit in its shade!

Answer (Rabah bar bar Chanah): The Mishnah teaches that one may not sit in a weak shadow (a morning or evening shadow which is longer than the tree's height).

Inference: The Mishnah discusses a weak shadow, but if he sat in a strong shadow (a shadow no longer than the tree's height) he is Tamei!

Rejection: No, even then he is Tahor;

The Mishnah forbids sitting in its shadow, even a weak shadow.

Version #2 - Question: Obviously, if he sat in its shade, he is Tahor!

Answer (Rabah bar bar Chanah): The Mishnah teaches that even if he sat in a strong shadow, he is Tahor.

Inference: The Mishnah discusses a strong shadow, but l'Chatchilah, one may sit in a weak shadow!

Rejection: No, even that is forbidden;

The Mishnah teaches that even if one sat in a strong shadow, he is Tahor.

(Mishnah): One may not pass under it. If he did, he is Tamei.

Question: Why is he Tamei?

Answer: Surely, something under the tree was offered to idolatry. The Mishnah is like R. Yehudah ben Beseira;

(Beraisa - R. Yehudah ben Beseira): Something offered to idolatry has Tum'as Ohel - "... va'Yochelu Zivchei Mesim";

Just like a corpse has Tum'as Ohel, also something offered to idolatry.

(Mishnah): If (the foliage was overhanging a Reshus ha'Rabim and) he passed under it, he is Tahor.

Question: Does the Mishnah say 'if he passed under it (b'Di'eved)', or 'he may pass under it (l'Chatchilah)'?

Answer #1 (R. Yitzchak ben Elazar): It says 'He may pass.'

Answer #2 (R. Yochanan): It says 'if he passed.'

They do not argue. If there is another path (no longer than this), one may not pass under. if there is no other path, it is permitted.

Rav Sheshes (was blind, his servant would transport him. He) told his servant 'when we pass under the Asherah, hurry'!

Question: What is the case?

If there is no other path, it is permitted. He need not hurry;

If there is another path, it is forbidden even if he hurries!

Answer: Really, there was no other path. An important person should be stringent to hurry.

(Mishnah): One may plant vegetables under it in winter (when its shade is bad for them), but not in summer;

One may not plant lettuce under it in summer or winter (shade is always good for lettuce).

R. Yosi says, even vegetables are forbidden in winter, because the leaves fall and fertilize them.

(Gemara) Inference: R. Yosi forbids Zeh v'Zeh Gorem (something that results from two or more causes, and one of the causes is forbidden, e.g. vegetables that are fertilized by the Asherah leaves and the soil), and Chachamim permit it;

Contradiction: Elsewhere, each holds just the opposite!

(Mishnah - R. Yosi): One grinds up (idolatry) and throws the dust to the wind, or casts it to the sea.

Chachamim: No. This would fertilize the ground (on which it lands). We may not get any benefit from idolatry - "Lo Yidbak b'Yadcha Me'umah Min ha'Cherem."

Answer #1 - part 1 (for R. Yosi): R. Yosi permits throwing dust of idolatry to the wind, for it will be scattered and not fertilize anything (Tosfos; Rashi - grinding up the idolatry was Mevatel it);

Question: How can we answer for Chachamim?

Answer #2: The opinions must be switched.

Completion of Answer #1: The opinions are not switched. We answer for R. Yosi like above;

Answer #1 - part 2 (for Chachamim): We explain Chachamim through Rav Mari's reasoning.

(Rav Mari brei d'Rav Kahana): (Even though a hide is worth more if it is flayed from the legs, one may not flay blemished Kodshim in this way, for it is bad for the meat. Even though we want to make the redemption value as great as possible,) the gain to the hide is offset by the loss to the meat.

Here also, the gain due to the leaves (fertilizer) is offset by the loss due to the shade.