Nedarim 33 - 39
"Tovat Hana'ah" describes a hardly discernible monetary value belonging to the owner of something he has to give away. It is described in detail in another gemara and referred to in ours.
In Mesechta Bechorot (27a) we are taught the following: If a person tithed his grain, he may be approached by a non-kohen before giving away the terumah and offered a sum of money in order to direct this terumah to the non-kohen's daughter's son, who is a kohen. A kohen, however, may not make such an offer -- either on his own behalf or on behalf of another kohen -- because this has the appearance of a kohen helping out in the granary in order to gain preference in receiving terumah, behavior which is considered a corruption of Hashem's covenant with the kohanim. Even when a non-kohen makes the offer, it is limited, adds the Jerusalem Talmud, to a situation in which the tither was planning to give the terumah only to one of two specific kohanim, and he uses the monetary inducement to influence his choice.
The potential for thus receiving such a monetary offer is called tovat hana'ah.
Whether this tovat hana'ah, with its potential for income, is considered actual money is discussed at length in other gemaras (Mesechta Pesachim 46b, Kiddushin 58a) and a practical application is whether a man can make kiddushin with a woman by giving her this right instead of actual money. Our ruling is in accordance with the view of the Sage Ulla that it is not considered real money.
In our own gemara, the question arises in regard to a situation in which one Jew uses his own grain to tithe the grain of another Jew. The conclusion of the gemara is that he can do so without the express consent of the other Jew. Although there is an argument to be made that the Jew benefiting from his generosity may object to his initiative because he wants to perform the mitzvah of tithing with his own grain, we nevertheless conclude that he considers it a benefit, and in such cases there is no need for actually appointing him an agent to do the tithing.
But who has the tovat hana'ah, asked Rabbi Yirmiyahu of Rabbi Zeira? The tither, or the owner of the grain which was tithed? The question is based on the fact that both of them are indispensable to the tithed part becoming terumah. The conclusion is that the tither, who used his grain to create terumah, has the right to the tovat hana'ah.
It is interesting to note that in describing a non-kohen's offer to "buy" the tovat hana'ah, the gemara speaks of his influencing the tither to give the terumah to his grandson who is a kohen. Why does it not suggest that he may be making such an offer in order to have the terumah given to his son-in-law, his grandson's father who is certainly also a kohen? Rambam (Laws of Terumah 12:20) writes to "daughter's son or sister's son or anything like that." This seems to indicate that a person is most likely to make the effort of paying for tovat hana'ah for a blood relative like a grandson or nephew rather than for a son-in-law or brother-in-law.
Mitzvot Without Limit
Each morning after saying the blessings on the Torah which Hashem gave us to study and live by, it is customary to actually study some Torah through reciting excerpts from Chumash, Mishna and Gemara. The mishna we recite is the first one in Mesechta Pe'ah which lists those mitzvot which have no set limits.
After learning in our gemara that bikur cholim -- visiting and caring for the sick -- is a mitzvah with no limits, which the Sage Rava explains as meaning that it is a mitzvah to visit even a hundred times in a day, we must wonder why this mitzvah is not included in the mishna's list. This question is actually raised by Rash in his commentary on Mesechta Pe'ah.
His resolution is that there is a distinction between bikur cholim performed with one's body and that performed by spending money to care for the sick. The Jerusalem Talmud states that the "no limit" standard mentioned in our gemara relates only to what one does with his body to tend to the ill, but does not apply to how much money to spend in that regard, because that has a limit just as there is a limit to how much charity one should give. Since the monetary facet of bikur cholim is not without limit, he concludes, it is omitted from the mishna because the bodily aspect is already included in "gemilut chasadim" -- acts of kindness -- already mentioned in the mishna.
(Maharsha must have had a version of Rash's commentary different than the one we have, because he offers what he calls an alternative resolution to that of Rash which is actually nothing more than what the Rash himself writes in our version of the text.)
Iyun Yaakov, however, does offer a genuine alternative response to the challenge of the Rash. Rambam (Laws of Mourning 14:4) writes in regard to the limitless nature of this mitzvah that "whoever increases his visits is considered praiseworthy so long as these visits do not constitute a disturbance." In contrast to the other things in the mishna which have no limit at all, bikur cholim can have a limit because at a certain point it can become counterproductive. For this reason it is left out of the mishna we recite each morning.