1) HALACHAH: A PREFERRED DOCTOR
The Gemara concludes that if one made a Neder not to give pleasure to his friend, he nevertheless is permitted to perform medical procedures for his friend. He is not permitted, however, to perform medical procedures for his friend's animal. The RAN (DH Ela) explains that the Gemara refers to a case where there are other doctors available to treat his friend. The Gemara is teaching that even though there are other doctors available, he is permitted to treat his friend because "not from all doctors does a person merit to be healed." Since the person who made the Neder might be the doctor who can heal his friend, he is permitted to treat his friend. The Ran cites the Yerushalmi as the source for this ruling.
The words of the Ran are the basis for the ruling of the SHULCHAN ARUCH regarding the obligation of a doctor to treat patients who come to him. The Shulchan Aruch (YD 336:1) rules that a doctor who refrains from doing a medical procedure to heal someone is consider as though he spills innocent blood. Even when there are other doctors who can perform the procedure, this doctor must treat the patient if he was called upon to do so.
RAV MOSHE FEINSTEIN zt'l (IGROS MOSHE OC I:131) writes that the Yerushalmi quoted by the Ran also teaches that if a doctor is requested on Shabbos to treat a patient whose life is in danger, he may desecrate Shabbos in order to come even though there are other doctors available. This applies, however, only when the patient requested him to be called, or he was already asked to come. If he was not specifically asked to come, he may not desecrate Shabbos to treat patients if there are other doctors available.
2) A PREFERRED VETERINARIAN
QUESTION: The Gemara concludes that if one made a Neder not to give pleasure to his friend, he nevertheless is permitted to perform medical procedures for his friend. He is not permitted, however, to perform medical procedures for his friend's animal. The RAN (DH Ela; see previous Insight) explains that the Gemara refers to a case where there are other doctors available to treat his friend. The Gemara is teaching that even though there are other doctors available, he is permitted to treat his friend because "not from all doctors does a person merit to be healed." The Ran writes that when there were no other doctors available, he is permitted to treat even his friend's animal, since doing so is like returning a lost object, which is permitted.
REBBI AKIVA EIGER questions the words of the Ran. How can the Ran compare healing his friend's animal to returning his friend's lost object? When he returns the lost object, he is not adding to or improving his friend's possessions. Therefore, he is permitted to return the object. In contrast, when he heals his friend's animal he improves his friend's possessions; healing the animal is comparable to feeding his friend's animal, which is prohibited. Why does the Ran (38b, DH she'Im Yirtzeh) prohibit feeding his friend's animal in order to sustain it, while here he permits healing the animal?
ANSWER: Perhaps healing the animal of his friend and returning his lost object are more comparable to each other for the following reason.
One is permitted to return a lost object to the Mudar Hana'ah because he fulfills two conditions: he fulfills a Mitzvah, and he is not giving the Mudar Hana'ah any pleasure from his own money (see Insights to Nedarim 33:3 and 38:2).
The Ran equates saving the life of one's animal (when there is no one else to do so) to returning a lost object because the act of saving the animal's life fulfills the same two conditions as returning a lost object: one does a Mitzvah by saving the animal, and one merely performs a service and does not provide benefit to his friend with his money. Although his friend may enjoy a gain from the recovery of his animal, treating the animal is permitted since he does so for the sake of the Mitzvah. In contrast, when he feeds his friend's animal from his own money, even if he does so in order to keep it alive his friend derives direct benefit from his money and thus the act is prohibited.
Perhaps Rebbi Akiva Eiger rejects this approach because he maintains that healing the Mudar Hana'ah's animal still is not comparable to returning his lost object, even though the Madir does not give the Mudar Hana'ah any money. Rebbi Akiva Eiger may understand that the Mudar Hana'ah may not experience any monetary gain from the Madir's acts, even if that gain is not a result of the Madir's money. The Ran (33b) emphasizes that returning a lost object is permitted since he is merely "chasing away a lion" ("Mavri'ach Ari"), an act which is not considered an act of giving pleasure. "Mavri'ach Ari" is the removal of imminent danger to the other's possessions; it is not the repair of possessions which have already been damaged. Rebbi Akiva Eiger understands that a sick animal is considered property which is already damaged and needs to be fixed (healed), and therefore healing it constitutes giving the owner monetary benefit and is not just "Mavri'ach Ari." Monetary benefit is prohibited even when it is given for the sake of a Mitzvah.
3) EATING MEAT AND DAIRY PRODUCTS AT THE SAME TABLE
QUESTION: The Gemara states that when a person makes a Neder to prohibit his friend from having pleasure from him, the two may eat at the same table but not from the same plate.
This Halachah seems to contradict the Halachah of the Gemara in Chulin (107b). The Gemara there states that one who is eating dairy foods is not permitted to eat at the same table as one who is eating meat foods, lest one eat from the other's food and transgress the prohibition of eating meat with milk. (See SHULCHAN ARUCH YD 88 who discusses the types of separation which permit them to eat at the same table.)
Since one who is prohibited by a Neder to derive pleasure from his friend is prohibited from eating his friend's food, why are they allowed to eat at the same table? Why is there no concern that the Mudar Hana'ah will eat his friend's food and thereby transgress the Isur d'Oraisa against violating a Neder?
(a) The RASHBA in Chulin answers that people are especially cautious not to transgress Nedarim. Therefore, there is no concern that one will accidentally eat food that is prohibited to him by a Neder.
(b) The ROSH answers that presumably two people who made a Neder not to have any pleasure from each other do not relate to each other on friendly terms, and they likely detest each other. Therefore, there is no concern that one will eat from the other's food. In fact, in such a case they may even eat meat and dairy products at the same table.
HALACHAH: The SHACH (YD 88:2) writes that a person (Reuven) is prohibited from eating at the same table with someone else (Shimon) who is eating food that is prohibited to him (Reuven) only when one of the following conditions exist:
1. Shimon is eating something that is permitted to others but not to Reuven (for example, Shimon is eating dairy products while Reuven is eating meat).
2. Shimon is eating food that is not inherently prohibited to Reuven, but is prohibited only because of a Neder.
3. The other person is eating bread that is prohibited. (Since bread is a basic staple, there is greater likelihood that Reuven will inadvertently eat from Shimon's bread.)
4. The other person is eating Chametz on Pesach (even if it is not bread). The law is more stringent on Pesach since even a minute amount that falls into Reuven's food prohibits it.
If Reuven does not know the other person (and thus is not likely to reach over and eat the other person's food), they are permitted to eat at the same table unless the other person is eating Chametz on Pesach.
Based on these conditions, one is permitted to eat at the same table as someone who is eating non-Kosher food, as long as the bread that he is eating is Kosher. If one does not know the other person, he is permitted to eat with the other person even if his bread is not Kosher.