Talmud - Nedarim 84b נדרים פ״ד ב׳

And the Rabbis say: He must designate poor man’s tithe by name, but he need not actually set it aside and give it to anyone, as a poor person cannot claim the tithe without bringing proof that he has a right to it. Rav Yosef now suggests: What, is it not that according to the one, i.e., the Rabbis, who says that the uncertainty as to whether or not poor man’s tithe had been separated by the am ha’aretz renders the produce forbidden as untithed produce [tevel], and therefore the owner of the produce must designate the poor man’s tithe by name, he holds that the owner of the produce has the benefit of discretion, meaning that he may give the poor man’s tithe to the poor person of his choice. And since he has the benefit of discretion, the option that a woman who vowed not to benefit from people should take poor man’s tithe is ineffective, as she would be receiving benefit from the owner of the tithe, since he could have given it to someone else.

Rav Yosef continues: And according to the one, i.e., Rabbi Eliezer, who says that he need not designate poor man’s tithe by name, he holds that the uncertainty as to whether or not poor man’s tithe had been separated by the am ha’aretz does not render the produce forbidden as untithed produce. And whenever the case is that uncertainty does not render the produce forbidden as untithed produce, the owner does not have the benefit of discretion and does not choose to which poor person he will give it. And therefore one who vowed not to benefit from people is permitted to derive benefit from poor man’s tithe, as he is not receiving it from anyone.

Abaye said to him: This proof is not conclusive, as it may be that everyone agrees that the uncertainty as to whether or not poor man’s tithe had been separated by the am ha’aretz renders the produce forbidden as untithed produce, and that Rabbi Eliezer and the Rabbis disagree with regard to this issue: Rabbi Eliezer maintains that amei ha’aretz are not suspected of failing to set aside poor man’s tithe. Therefore, one who purchases demai from an am ha’aretz need not be concerned that its poor man’s tithe might not have been set aside. Rabbi Eliezer maintains this opinion because were the am ha’aretz to declare all his property ownerless and therefore become a poor man, and then take the poor man’s tithe himself, he would suffer no loss when he set aside this tithe, and therefore it is assumed that he separated it.

And the Rabbis maintain that while it is theoretically possible for one to avoid having to actually part from his poor man’s tithe, this is uncommon, as a person does not ordinarily declare his property ownerless for this purpose, as he is afraid that perhaps someone else will acquire it in the meantime. Consequently, one who sets aside poor man’s tithe from his produce is assumed to incur a loss, and therefore amei ha’aretz are suspected with regard to this tithe. Accordingly, no satisfactory explanation has yet been given as to why the baraita permits a woman who vowed not to derive benefit from people to take poor man’s tithe.

Rava says that it is possible to explain the apparent contradiction between the sources with regard to benefit from poor man’s tithe without recourse to a tannaitic dispute: Here, the mishna is referring to poor man’s tithe distributed in the owner’s house, i.e., poor man’s tithe that had not been distributed in the threshing floor but was brought home and must now be distributed to the poor who visit the house, as the term giving is written in the verse with regard to such a tithe: “And you shall give to the Levite, to the stranger, to the orphan, and to the widow” (Deuteronomy 26:12), and the owner is entitled to give the tithe to the poor man of his choice, as the benefit of discretion is conferred upon him. Due to that reason, it is prohibited for one who vowed not to derive benefit from people to derive benefit from this type of poor man’s tithe.

There, however, the baraita is referring to poor man’s tithe that is distributed in the threshing floor. Since with regard to such a tithe it is written: “And you shall leave it at your gates” (Deuteronomy 14:28), the owner cannot designate it for a particular person, and any poor person who comes by may take it from him. As the owner lacks the benefit of discretion, one who vows not to benefit from people is permitted to benefit from this poor man’s tithe.

§ The mishna teaches that if one said: I will not let priests and Levites benefit from me, they can take the priestly and Levitical gifts from him against his will. The Gemara notes: Apparently, the benefit of discretion to give his teruma and tithes to the priest or Levite of his choice is not considered to have monetary value. The priests and Levites can take the gifts from the owner of the produce against his will, and the latter is not regarded as having conferred benefit upon them.

But say the latter clause of the mishna, which states that if the person said: I will not let these specific priests and these specific Levites benefit from me, these gifts are taken by others. But these priests and Levites specified in his vow may not take these gifts. Apparently, this ruling indicates that the benefit of discretion is considered to have monetary value, and therefore the owner can prohibit specific priests or Levites from deriving benefit from him.

Rav Hoshaya said: This is not difficult; this second ruling is in accordance with the opinion of Rabbi Yehuda HaNasi, and that first ruling is in accordance with the opinion of Rabbi Yosei, son of Rabbi Yehuda, as it is taught in a baraita: If one steals another’s untithed produce and eats it, he must pay him the value of his untithed produce, i.e., the full value of what he stole. This is the statement of Rabbi Yehuda HaNasi. Rabbi Yosei, son of Rabbi Yehuda, disagrees and says: He pays him only the value of the non-sacred produce it contained. The thief does not have to pay him the value of the teruma and tithe included in the untithed produce, as these portions do not belong to the owner of the produce. What, is it not the case that they disagree about this:

Traduction : The William Davidson digital edition of the Koren Noé Talmud, with commentary by Rabbi Adin Even-Israel Steinsaltz.

Nedarim 84b explores whether poor man's tithe must be formally designated and how this affects a vow forbidding benefit from others.