וַיְדַבֵּ֣ר יְהוָה֮ אֶֽל־אַהֲרֹן֒ וַאֲנִי֙ הִנֵּ֣ה נָתַ֣תִּֽי לְךָ֔ אֶת־מִשְׁמֶ֖רֶת תְּרוּמֹתָ֑י לְכָל־קָדְשֵׁ֣י בְנֵֽי־יִ֠שְׂרָאֵל לְךָ֨ נְתַתִּ֧ים לְמָשְׁחָ֛ה וּלְבָנֶ֖יךָ לְחָק־עוֹלָֽם׃
И сказал Господь Аарону: 'И Я, вот, Я дал тебе заряд Моих подношений; даже из всех освященных вещей сынов Израилевых Я отдал их на освященную часть и сыновьям вашим как навеки.
Teshuvot haRashba Meyuchas LehaRamban
Answer: Answer: This is a profound question and something that the early scholars discussed and in which they became entangled – why we recite a blessing on some of them and we do not recite a blessing on all of them; and which do we recite a blessing over, and which do we not recite a blessing over. And the matter is not dependent upon one reason, such that I should give you one principle about them. Rather: We do not recite a blessing over any commandment that does not have an action, such as the release of monies [outstanding loans] and that which is similar to it. And likewise do we not recite blessings over anything that is given over to the court, such as adjudication – lest the litigants not accept their opinion – as well as any other commandment like that. And we do not recite a blessing over a commandment that is not completely dependent upon the one that does it, since it is possible that his fellow will not agree to it, such that it will come out that the act will be nullified, such as gifts to the poor, loans to the needy, giving charity, severance [to liberated slaves] and that which is similar to them. And likewise any commandment that comes through a sin, such as returning what was stolen, or the return of interest. As we were not commanded to steal in order to return [what we stole], nor to take the mother [bird] over the children so that we can then send it away, and all that is similar to these. And we likewise not recite a blessing over the giving of gifts to the priesthood. For a Jew is not giving from what is his, but rather acquires it for the priest and acquires it from the “table of the High One.” And the giving of the shekel-coin once a year is similar to this, since everything is from You, and they give to You from Yours (alluding to I Chronicles 29:14). But one does recite a blessing over the redemption of a son, and over the separation of the challah-dough, and tithes. For he is not reciting the blessing over the giving but rather over the separation or redemption, which are dependent upon [his actions]. And we do not recite a blessing over a commandment the core of which is not a commandment, such as levirate release and levirate marriage, since the core [of it] is on account of being fruitful and multiplying. And likewise divorce, since there are some divorces that are sinful, such as one who did not find a licentious matter with her but divorces her [regardless]. And [this is the case], even though it is sometimes a commandment, such as [divorcing] those women he married sinfully. For it is a commandment to divorce them. But the rabbis did not distinguish concerning divorce, that one recite a blessing in some of them and not recite a blessing in [others] of them. And we likewise do not recite a blessing over the death penalties of the court, since the Holy One, blessed be He, is concerned for His creatures and does not desire the death of the wicked. And thus we do not recite a blessing over them. And it is like that matter that they said, that we do not recite a blessing over a punishment. And it is also for that reason that we do not recite a blessing over final waters [at the end of a meal], since they come on account of Sodomite salt and we do not recite a blessing over a punishment [this salt being a result of the destruction of Sodom]. And likewise over visiting the sick, comforting mourners, bringing peace between a person and his fellow, since they depend upon others. For it is possible that they will not accept it from him, so they have the ability to uproot this commandment from him. And from where do we [know] that we do not recite a blessing over a commandment that comes through a sin? For it is learned [in a baraita]: Rabbi Eliezer ben Yaakov says, "Behold, one who stole a seah of wheat, ground it, kneaded it, baked it, etc. [how can he recite a blessing before separating challah-dough, as it is stated:] The robber who recites a blessing [blasphemes] (Psalms 10:3)." And Rabbah says [that the reason behind the statement] of Rabbi Eliezer ben Yaakov is because it was a commandment that comes through a sin (Bava Kamma 94a). And from where do we [know] that any commandment that is possible to uproot is considered uprooted, even though it is not uprooted now? Since we learn [in a mishnah] in the chapter [entitled] Elu Naarot (Ketuvot 39a:8), "How does [a rapist] drink from 'his vessel?' Even if [the woman he raped] is lame, even if she is blind, etc. [he must seek to marry her. But] if she is unfit to enter the Jewish people, he is not permitted to keep her [as his wife], as it is stated, And to him she shall be as a wife (Deuteronomy 22:29) – a woman who is suitable for him." And we say about this in the Gemara, "But let the positive commandment push off the negative commandment! He said to him, '[When do] we say, let the positive commandment push off the negative commandment? For example, circumcision on a sore of tzara’at, since it is impossible to fulfill the positive commandment [otherwise]. However here if she did not want [to marry him], would the positive commandment arrive at all?'" Hence, since it is possible to uproot the positive commandment, it is as if it is not there, even though it has still not been uprooted. For it is not absolute. As the [Torah] only required him to marry her for her benefit. So when she says, “I do not want that benefit,” the positive commandment in this is uprooted. And we learn from [this case where the fulfillment of the commandment can be uprooted by its recipient to other such cases, such as] honoring father and mother and getting up in front of one's teacher. As it is possible to uproot their positive commandments, since a father who forgoes his honor [may do so]. And from where do we [know] that we do not recite a blessing over gifts to the priesthood? Because one acquires it from the 'table of the High One.' And likewise with that which was stolen from a convert, which is from the gifts to the priesthood (if the convert dies without any living relatives), we also say it is God's, and He gave it to the priests. And it is like we say in Bava Kamma, "We understand from this that one who gives gifts to the priesthood is not giving from what is his, but they are rather the Merciful One's, as it is written, I hereby give you charge of My gifts (Numbers 18:8)." Rabbi Yosef Pelet and the Raavad.