1) "HA'MEKAYEM B'KIL'AYIM"
OPINIONS: The Gemara quotes a Beraisa in which the Tana Kama and Rebbi Akiva disagree about the liability for transgressing the prohibition of Kil'ayim. The Tana Kama states that one who weeds out bad crops in order to help the Kil'ayim grow, or one who covers the seeds with dirt to help them grow, receives Malkus. Rebbi Akiva states that even one who is merely "Mekayem" Kil'ayim receives lashes. To what act does Mekayem Kil'ayim refer?
(a) The ARUCH (cited by Tosfos, DH Rebbi Akiva) explains that when one allows Kil'ayim to grow in his field, he is punished with Malkus even though he did not plant the seeds. The Aruch explains that although there is a general principle that one does not receive Malkus for a Lav she'Ein Bo Ma'aseh (a prohibition that is transgressed passively, without an action), Rebbi Akiva does not agree with this principle and maintains that one receives Malkus even for a passive transgression. This is also the opinion of the RIVAN (Makos 21b, DH Mi Mishkachas).
(b) TOSFOS argues with the Aruch and explains that "Mekayem" refers to building a fence of thorns around the Kil'ayim in order to protect them. Accordingly, Rebbi Akiva agrees that one does not receive Malkus for a Lav she'Ein Bo Ma'aseh, and in this case one transgresses the prohibition actively (by building the fence). This is also the opinion of the RITVA here, the TOSFOS HA'ROSH in Moed Katan (2b), and the ME'IRI there.
(c) The opinion of RASHI is not clear. Tosfos here writes that he agrees with Rashi (DH Afilu) that "Mekayem" refers to building a fence of thorns in order to protect the Kil'ayim. However, in Moed Katan (2b, DH Af ha'Mekayem), Rashi implies that it refers to one who sees Kil'ayim in his field and lets it remain there, as the Aruch explains. How is this apparent contradiction in Rashi to be reconciled?
1. The BEIS HA'LEVI (1:35:2) writes that Rashi explains "Mekayem" like the Aruch, in contrast to Tosfos' understanding of Rashi, and it is possible for a person to receive Malkus for letting Kil'ayim exist. However, the prohibition of letting Kil'ayim exist applies only to the owner of the plants (which is the case discussed in Moed Katan). The Gemara here, however, is discussing one who is Mekayem the Kil'ayim of a Nochri. In this case, Rashi cannot explain "Mekayem" to mean merely letting it exist, since there is no obligation to destroy the Kil'ayim of a Nochri. This is why Rashi here explains that the Gemara must be referring to one who does an action that shows that he wants the Kil'ayim to exist.
2. The Beis ha'Levi gives another explanation. When a person begins a transgression with an action, it is possible for other, passive prohibitions that result from the initial action to be considered as though they, too, are transgressed actively. For example, one receives Malkus for wearing Kil'ayim (Sha'atnez) if he does not remove the prohibited garment, even though the failure to remove the garment is a passive transgression. Since the person initially performed an action which led to the present prohibition (of not removing the garment), it is considered as though he has transgressed the present prohibition with an action. Rashi in Moed Katan understands that when the Gemara there discusses a person who is Mekayem Kil'ayim, it is referring to the same Jew who planted the seeds in the first place. Since he initially performed an action when he planted the seeds, his present, passive transgression of wanting the Kil'ayim to remain is considered an action. In contrast, the Gemara here in Avodah Zarah is referring to a case in which the Kil'ayim was planted by a Nochri, and thus Rashi here explains that the Jew receives Malkus only because he did an action of building a fence to protect the Kil'ayim. This is also the explanation of the KORBAN ELITZUR (to Avodah Zarah) and the MEGILAS SEFER (Lavin #279). (See also Insights to Makos 21:3.)
(d) TOSFOS in Bava Kama (81a, DH Ein) writes that when Rebbi Akiva says that one is punished with Malkus for Mekayem Kil'ayim, he does not mean that the person actually receives Malkus, since it is a Lav she'Ein Bo Ma'aseh. Rather, he means merely that it is Asur mid'Oraisa. The RI KURKAS (Kil'ayim 1:3) and the Korban Elitzur explain that Tosfos means that one receives Malkus d'Rabanan according to Rebbi Akiva. (See YAD DAVID to Makos 21b for an alternative explanation of the words of Tosfos.)
(e) The KESEF MISHNEH (Kil'ayim 1:3) gives another explanation. The Gemara in Moed Katan, after asking a question on the Beraisa, suggests that the Beraisa is expressing not two opinions, but rather only one opinion -- that of Rebbi Akiva. The Beraisa is saying that one who weeds out bad crops, or covers the seeds with dirt, in order to help the Kil'ayim grow receives lashes because he has transgressed the Isur of Mekayem Kil'ayim, for Rebbi Akiva maintains that even Mekayem is prohibited. Accordingly, Rebbi Akiva is saying that only when one does an action with the seeds themselves does he transgress the prohibition of Mekayem Kil'ayim. However, building a fence around Kil'ayim, which does not involve an action with the seeds themselves, is not punishable with Malkus. A similar explanation is given by RABEINU CHANANEL (in Moed Katan), who states that Mekayem refers to one who works the land and causes the plants of Kil'ayim to grow better. (Y. MONTROSE)
2) HALACHAH: THE DEFINITION OF A "GER TOSHAV"
OPINIONS: The Gemara quotes three opinions about who is a Ger Toshav. Rebbi Meir maintains that a Ger Toshav is a Nochri who accepts upon himself, in front of three "Chaverim" (Talmidei Chachamim), not to worship idols. The Chachamim say that a Ger Toshav is a Nochri who accepts upon himself to observe the seven Mitzvos of Bnei Noach. Acherim maintain that the above opinions are incorrect, and that a Ger Toshav is a Nochri who accepts all of the Mitzvos except for not eating Neveilos (animals that were not slaughtered properly). What is the Halachah?
(a) The RAMBAM (Hilchos Melachim 8:10-11) writes that any Nochri who accepts the seven Mitzvos of Bnei Noach in front of three Chaverim is considered a Ger Toshav. The Rambam adds an interesting application to the laws of Ger Toshav. He states that any Nochri who is careful to observe these Mitzvos is considered one of the "Chasidei Umos ha'Olam" (righteous of the nations) and earns a share in Olam ha'Ba. However, this is true only if he does these Mitzvos because Hash-m commanded them in the Torah and told the Jewish people that Nochrim are obligated to fulfill these seven Mitzvos. If he does these Mitzvos merely because he thinks that they are logical, moral principles, he is not considered a Ger Toshav and is not one of the "righteous of the nations," but rather he is merely a sensible person.
The TO'AFOS RE'EM on the SEFER YERE'IM (233:2) suggests that the Yere'im argues with the last statement of the Rambam. The Yere'im cites the Gemara in Kidushin (33a) that discusses the obligation to stand up for an elderly Nochri. He writes that one should stand up only for a Nochri who observes the seven Mitzvos of Bnei Noach. However, the Gemara says that Abaye stood up for a "Saba Arama'i" (an old Aramean) who was passing by (we have a slightly different wording in the texts of our Gemara). If Abaye stood up for him only because he was a Ger Toshav, then why does the Gemara there call the Nochri a "Saba Arama'i," which has a derogatory connotation? The Gemara should call him a Ger Toshav! The Yere'im answers that the Gemara nevertheless refers to a Ger Toshav by the title of "Saba Arama'i."
The To'afos Re'em writes that the Yere'im's answer shows that he argues with the view of the Rambam. If the Yere'im maintains that a Nochri is called a Ger Toshav only when he observes the seven Mitzvos because of Hash-m's command, then why does the Yere'im not answer simply that although the Saba Arama'i observed the seven Mitzvos, he is not referred to as a Ger Toshav because he observed them for logical reasons? From the fact that the Yere'im does not give this answer, the To'afos Re'em infers that the Yere'im argues that one can be a Ger Toshav as long as he observes the seven Mitzvos of Bnei Noach, regardless of his motive for observing them (see ONEG YOM TOV OC 19).
(b) RASHI's opinion is not clear. It seems logical that the Halachah should follow the opinion of the Chachamim mentioned in the Gemara here, as the Rambam and others rule (see SHULCHAN ARUCH YD 124:2). However, Rashi in Sanhedrin (96b, DH Ger Toshav) explains that a Ger Toshav is a Nochri who "did not accept the other Mitzvos, and he accepted not to serve idols." This, however, is the opinion of Rebbi Meir! Why does Rashi choose the opinion of Rebbi Meir over the opinion of the Chachamim?
The BE'ER SHEVA (Sanhedrin 96b) explains that Rashi's statement there does not necessarily mean that he does not rule like the Chachamim. Rather, their opinion is not relevant to the discussion there. The Gemara here (65a) concludes that this argument is not a general question concerning what constitutes a Ger Toshav. Rather, the argument here concerns only whether we are obligated to help sustain such a person (see BI'UR HA'GRA YD 124:4, who makes this point with regard to Yayin Nesech). Rashi agrees that in this argument, the Halachah follows the view of the Chachamim, and thus we give special support only to one who observes all of the seven Mitzvos of Bnei Noach. Regarding the definition of a Ger Toshav for all other matters, Rashi understands that even a Nochri who merely does not worship idols is considered a Ger Toshav.
The MARGOLIYOS HA'YAM points out that Rashi earlier in Avodah Zarah (24b, DH Ger Toshav) defines a Ger Toshav as one who accepted the seven Mitzvos of Bnei Noach. How does Rashi rule? The Margoliyos ha'Yam explains that the Gemara in Sanhedrin is discussing the specific case of Na'aman, a Nochri king who was important and esteemed (see Melachim II 5:1), who likely did not eat Ever Min ha'Chai or transgress the other Mitzvos of Bnei Noach. After being miraculously cured by Elisha, he exclaimed (ibid. 5:17) that he would no longer offer sacrifices to alien gods. The Margoliyos ha'Yam understands that Rashi in Sanhedrin is teaching that when the Gemara says that Na'aman was a Ger Toshav, it means that Na'aman did not have to accept all of the seven Mitzvos, because he already was observing six out of the seven. The Gemara there refers to his final commitment not to serve idols, which made him into a Ger Toshav. (Y. MONTROSE)