1) DERIVING PLEASURE FROM LEARNING TORAH
QUESTION: The Mishnah teaches that when one makes a Neder to prohibit himself from deriving pleasure from his friend, he may not use items that are even partially owned by his friend (which his friend owns in partnership). Consequently, he may not use the synagogue of the town and the Sefarim in the synagogue, because those items are partially owned by his friend (who pays his dues to the community fund).
When the Mishnah says that he may not use the Sefarim in the synagogue, it refers to the Sefarim of Tanach and other Sifrei Kodesh used for the Mitzvah of Talmud Torah. Why, though, is the person prohibited from using those Sefarim? The principle of "Mitzvos Lav l'Hanos Nisnu" teaches the physical benefit one derives from a Mitzvah is not considered benefit (Rosh Hashanah 28a). Accordingly, he should be permitted to use the Sefarim!
ANSWERS:
(a) The RASHBA asserts that because of this question, the Girsa of the Mishnah must be amended and this statement omitted from the Mishnah. He rules that the person is permitted to use the Sefarim because "Mitzvos Lav l'Hanos Nisnu" and thus the benefit he derives from his friend's share of the Sefarim is not considered benefit.
(b) RABEINU AVRAHAM MIN HA'HAR suggests a unique approach to answer this question. He writes that the concept of "Mitzvos Lav l'Hanos Nisnu" applies only to Mitzvos which involve an obligation to perform a physical act. When one performs such Mitzvos, he does not do the act in order to have physical pleasure from it but to fulfill the will of Hash-m. In contrast, the essence of the Mitzvah of learning Torah is to understand the truth of the Torah and to enjoy the accomplishment of perceiving the Divine wisdom underlying the commandments of Hash-m. Therefore, it cannot be said that the Mitzvah of learning Torah is not an act of Hana'ah, pleasure. It is an act of Hana'ah, and therefore the Mudar Hana'ah may not use Sefarim owned in part by his friend.
The RAN (37a, DH Amar Shmuel) agrees with the Rashba that the concept of "Mitzvos Lav l'Hanos Nisnu" applies also to learning Torah. The AYELES HA'SHACHAR (16b) writes that the Ran agrees that having pleasure from Torah learning is an integral part of the Mitzvah (as Rabeinu Avraham Min ha'Har asserts), but the Ran maintains that since that pleasure is part of the commandment to learn Torah, the principle of "Mitzvos Lav l'Hanos Nisnu" applies the same way it applies to every other Mitzvah. (See also MESHOVEV NESIVOS 72:17, DH Gam, who discusses the issue of whether the Mitzvah of learning Torah is included in the principle of " Mitzvos Lav l'Hanos Nisnu.")
HALACHAH: This question has practical relevance to other Halachos. For example, when one buys a new object that is valuable to him and causes him joy, he should recite the blessing of "Shehecheyanu" (see Shulchan Aruch OC 223). The MAGEN AVRAHAM (OC 223:5) writes that when one buys Sefarim (even expensive ones) he should not recite the blessing of "Shehecheyanu." The blessing was instituted only for one who derives pleasure from the new object he bought, but the pleasure one derives from new Sefarim is not considered pleasure because "Mitzvos Lav l'Hanos Nisnu." The Magen Avraham's ruling seems to be in agreement with the view of the Rashba. According to Rabeinu Avraham Min ha'Har, one should recite "Shehecheyanu" upon the purchase of new Sefarim, because the pleasure of learning Torah is considered pleasure (and "Mitzvos Lav l'Hanos Nisnu" does not apply). (However, it is possible that even Rabeinu Avraham Min ha'Har would agree with the ruling of the Magen Avraham for a different reason. Perhaps one recites the blessing of "Shehecheyanu" only when he experiences physical pleasure from the new object. The pleasure one receives from new Sefarim is not physical pleasure, and thus he should not recite "Shehecheyanu.")
The SHA'AREI TESHUVAH (ad loc.) quotes other Acharonim who disagree with the Magen Avraham, and the MISHNAH BERURAH (223:19) cites the CHAYEI ADAM who also disagrees with the Magen Avraham. The Chayei Adam reasons that since a person who acquires a new Sefer is happy with his acquisition, he should recite the blessing because the blessing was instituted for the joy which one experiences and not for the use he will derive from the Sefer. The Mishnah Berurah implies that in practice one preferably should not recite "Shehecheyanu" upon the purchase of new Sefarim, but he concludes that one who recites "Shehecheyanu" should not be admonished ("Ein Limchos"). (See also Shulchan Aruch OC 22 and the BI'UR HALACHAH there with regard to reciting "Shehecheyanu" upon the purchase of a new Talis and Tefilin.)