1) HALACHAH: HOW MANY LEAVES MUST REMAIN ON A DRY HADAS
OPINIONS: The Beraisa states that if most of the leaves of the Hadas branch have dried out, but "it still has three Badim of moist leaves" it is valid. Rav Chisda adds that the moist leaves must be at the top of each branch.
What does the Beraisa mean when it says that the Hadas must have "three Badim of moist leaves" left in order for the Hadas to be valid?
(a) RASHI explains that the Beraisa means that each of the three branches ("Badim") of Hadas must have three moist leaves (on top, according to Rav Chisda). However, the words, "It still has three branches of moist leaves" is unclear. What is "it" that still has three branches?
The RA'AVAD (cited by the ROSH) explains that "it" is the Lulav. The Beraisa is saying that "the Lulav still has three [Hadas] branches of moist leaves," which means that each of those three branches has three moist leaves on it.
The RITVA translates the word "Badim" differently. He explains that "Badim" means "Kanim," or "sets of leaves." His explanation of the Beraisa concurs, in practice, with Rashi's explanation: each Hadas must have at least three moist leaves left in order to be valid. When the Beraisa says "it still has three Badim of moist leaves," the word "it" refers to each of the three Hadas branches. The Beraisa is saying that if "the three branches of Hadas still contain three sets (trios) of moist leaves (one trio of leaves per branch)," then it is valid. That is, if each Hadas branch has a set of three moist leaves left on top, it is valid.
(b) The ROSH understands the Gemara differently. He explains, like the Ritva, that the word "Badim" refers to "Kanim" ("sets of leaves"). However, he says that the Beraisa refers to one branch of Hadas and not to three. The Beraisa is saying that if "it (one branch of Hadas) still contains three sets of moist leaves" anywhere on the branch, then it is valid.
According to the Rosh, however, what does Rav Chisda mean when he says that the three sets of leaves must be "at the top of each"? At the top of what must the three sets of leaves be? The Beraisa discusses only one branch, with one top (with space for only one set of three leaves)! How can all three sets of leaves be at the top of one branch?
The Rosh explains that Rav Chisda does not mean that the moist leaves must be at the top of the branch. Rather, he means that of the three sets of leaves on each branch, only one of the three leaves of each set must be moist, and he explains which leaf must be moist. The lowest leaf of the set, which usually is on top of (i.e. covers) the upper two leaves of the trio, must be moist, because it is the one that is most visible.
HALACHAH: The SHULCHAN ARUCH (OC 646:8) cites both opinions. The MISHNAH BERURAH (646:26) rules that the Halachah follows the first opinion, that each branch needs only three moist leaves left on top in order to be valid.
2) PICKING BERRIES OFF OF A HADAS BRANCH ON YOM TOV
QUESTION: Rebbi Eliezer b'Rebbi Shimon maintains that one may pick the berries off of a Hadas branch on Yom Tov, and the act is not considered "Tikun Kli" (the formation of a new, usable vessel), even though he makes the Hadas branch valid for use for the Mitzvah.
RASHI explains that one may pick the berries because his intention is not to fix the Kli, but to eat the berries. The Tikun Kli that results is a Davar she'Eino Miskaven, since he had no intention to make a usable Kli.
The Gemara asks that even though the act is a Davar she'Eino Miskaven, it is a Pesik Reishei -- even though he had no intention to make a usable Kli, his action definitely will result in the formation of a usable Kli. In the case of a Pesik Reishei, everyone agrees that the act is forbidden.
The Gemara answers that he has another valid Hadas branch, and thus he does not need the branch from which he removes the berries.
How does the Gemara's answer resolve the problem that his act is a Pesik Reishei? Even though he has another Hadas branch, when he picks the berries from the first one he turns it into a usable Hadas. His act is still a Pesik Reishei.
(a) TOSFOS (DH Modeh) explains that since the person has another Hadas and he does not need this one, his act (that makes this one fit for use) is considered a Melachah she'Einah Tzerichah l'Gufah, for which one is exempt according to Rebbi Shimon.
However, Rebbi Shimon agrees that a Melachah she'Einah Tzerichah l'Gufah is prohibited mid'Rabanan. Why is it permitted in this case?
1. Tosfos here explains that Rebbi Eliezer (the son of Rebbi Shimon) permits the act l'Chatchilah when it will enable a Mitzvah to be fulfilled (the Mitzvah of Arba'as ha'Minim). (Even though the person picks the berries from the Hadas in order to eat them and does not intend to use this Hadas for the Mitzvah, since it is possible that someone else will need this Hadas for the Mitzvah, the Rabanan permitted a Melachah she'Einah Tzerichah l'Gufah in this case.)
2. TOSFOS in Shabbos (103a) suggests another reason for why this Melachah she'Einah Tzerichah l'Gufah is permitted l'Chatchilah. Removal of the berries is not a complete Tikun Kli. He does not actually form a new item when he removes the berries from the branch; he merely makes the branch fit for use for the Mitzvah. His act is considered a "Tikun Kal," a "light" Tikun, since it merely gives the item a new Halachic status and makes it valid for the Mitzvah. The Rabanan did not prohibit such a Tikun when it is a Melachah she'Einah Tzerichah l'Gufah.
3. TOSFOS in Kesuvos (6a) suggests another reason for why Rebbi Eliezer b'Rebbi Shimon permits one to perform a Melachah she'Einah Tzerichah l'Gufah in this case. If the person picks the berries from the Hadas and never uses the Hadas for the Mitzvah, it will not be considered a Kli at all. It attains the status of a Kli only retroactively, when the person decides to use it as a Hadas on Yom Tov. Since he has another Hadas, and he may never need this Hadas for the Mitzvah, his act of picking the berries is only a Safek Melachah she'Einah Tzerichah l'Gufah, and not a definite Melachah she'Einah Tzerichah l'Gufah, and thus the act is permitted.
(b) The ARUCH (Erech "Pasak," "Savar") cited by Tosfos in Shabbos (103a) explains that a Pesik Reishei is forbidden only when one benefits from the act. When one derives no benefit from the result of the Pesik Reishei, it remains a permitted Davar she'Eino Miskaven (according to Rebbi Shimon).
(Rashi in Shabbos (75a, DH Tefei) seems to express an opinion similar to that of the Aruch, but Rashi adds that a Pesik Reishei is permitted only when the result of the Melachah is detrimental to the person who did it, and not if he is merely indifferent to it.)
(c) RASHI appears to have an entirely different approach to the Gemara. Rashi explains that a Tikun Kli depends on one's personal preferences. That is, a Kli is not an item which has an objective definition. Rather, if a person does not want to use the item which he makes (such as the valid Hadas that he makes when he picks the berries from it), it will not be a Kli; it will be called a "berryless Hadas," but not a Hadas which can be used for the Mitzvah. Even if it is later used for the Mitzvah, the act of picking its berries is not considered (retroactively) an act of Tikun Kli, because the one who picked the berries did not intend to use it for the Mitzvah.
Rashi is consistent with his opinion elsewhere. In Shabbos (103a, DH b'Ar'a d'Chavrei), Rashi writes that if a person picks weeds from someone else's garden on Shabbos because he wants to eat the weeds and not because he wants to improve the quality of the garden (since it is not his garden), he is exempt from punishment for desecrating Shabbos, because he did not intend to improve the garden by weeding it. Since it was not his intention to beautify the garden, it is not considered as though he beautified it. It is clear from the words of Rashi that beautifying a garden is subjective; the definition of his act depends upon his intention. This opinion is expressed by the MAGID MISHNEH (Hilchos Shabbos 10:17, 12:2) as well.
(Tosfos in Shabbos rejects this explanation, because it asserts that the reason why Rebbi Eliezer b'Rebbi Shimon permits one to pick the berries is not because the formation of the new Kli is a Davar she'Eino Miskaven which is permitted, but because one does not make a new Kli at all. The Gemara should have prefaced this answer with the word "Ela" ("rather"), since it is an entirely new answer for why one is permitted to pick the berries.)