Rav Pesach, Baruch she'Kivanta! Your question is asked by the Keren Orah on Menachos 52a to Tosfos DH Gazru.

1) The Keren Orah writes that what Tosfos writes -- that if it would be Hekdesh they could not have sprinkled from it -- is not so straightforward, because the Beis Din possesses the power to make the ashes Hekdesh but nevertheless to also say that one may only perform the Mitzvah with the ashes, namely to sprinkle with it. The Keren Orah concludes that if one does sprinkle, it is not considered that one is deriving forbidden benefit from Hekdesh, because the sprinkling is a Mitzvah. In other words, since the sprinkling is a Mitzvah, we say "Mitzvos Lav Leihanos Nitnu," and this should therefore be permitted.

2) The Olas Shlomo on Zevachim 46a to Tosfos DH Hu (which is a similar Tosfos to our Tosfos in Yoma 59b, and also states that one cannot say that the Beis Din was Mekadesh the ashes, because otherwise how could they sprinkle with them) answers that Tosfos does not actually mean that the reason why it would be forbidden to sprinkle is because this represents deriving benefit from the water of the ashes, because since "Mitzvos Lav Leihanos Nitnu" the latter should be permitted.

3) The Olas Shlomo does mention a possible answer which he then rejects. This is based on Rosh Hashana 28a, where Rava stated that if someone had vowed not to derive benefit from his friend, the friend can nevertheless sprinkle the Parah Adumah water on him in the winter but not in the summer. In the winter he is only gaining a Mitzvah, while in the hot summer there is also physical enjoyment that he receives when the sprinkling cools him down, so "Mitzvos Lav Leihanos Nitnu" cannot apply to permit physical enjoyment.

Therefore, one might suggest that our Tosfos is referring to the summer months and consequently it is forbidden to sprinkle.

However, the Olas Shlomo writes that it would be a forced answer to claim that Tosfos' words only applies in the summer.

4) Finally, the Olas Shlomo explains that there is a different reason why Tosfos writes that one may not sprinkle, not because this represents benefit from Hekdesh. The reason why it is forbidden is that when one sprinkles the ashes, one is actively destroying a holy item. It is forbidden to destroy a Hekdesh item even if one does not derive benefit in the process.

5) The Olas Shlomo compares this to what Tosfos writes in Zevachim 76b DH Log. Tosfos writes that if one pours oil of Hekdesh on the toes of someone who is not a Metzora, this is considered that one has thrown away holy oil which is forbidden. Similalrly, the Olas Shlomo argues that one may not use Hekdesh ashes to prepare the Mei Chatas, because when one sprinkles it this is considered as destroying the property of the Beis ha'Mikdash.

6) In summary, when one sprinkles the Mei Chatas derived from ashes belonging to Hekdesh, this is not considered as forbidden benefit, because "Mitzvos Lav Leihanos Nitnu." However, there is a different resason for why it is forbidden, and that is that by sprinkling water derived from Hekdesh, one is destroying the property of Hekdesh.

Kol Tuv,

Dovid Bloom

I found a different answer to this question (in Otzar ha'Chochmah) in a Sefer on Maseches Yoma called Chukas ha'Yom, by Rav Shalom ha'Kohen Brander. It is on page 238 of the Sefer.

1) His answer is based on the Gemara in Rosh Hashanah (28a). The conclusion of Rava there is that if someone blew the Shofar on Rosh Hashanah with Shofar of an animal which had been specified to be a Korban Olah or a Korban Shelamim, he thereby fulfills the Mitzvah. Even though it is forbidden to derive benefit from a sanctified Korban, the rule is that Mitzvos Lav Leihanos Nitnu, and thus doing the Mitzvah is not considered as receiving Hana'ah, benefit, from the object.

2) However, when the Rambam records this Gemara in Hilchos Shofar 1:3, he writes that one should not blow with the Shofar of an Olah, but if he did blow with it he is Yotzei. The Rambam questions his own words: Why is this not considered as receiving benefit from the Korban, since one enjoys hearing the sound of the Shofar? He answers that Mitzvos were not given to us for Hana'ah. The Rambam continues that it follows that if someone had made a vow not to receive benefit from a Shofar, he may blow with this Shofar in order to perform the Mitzvah.

3) The interesting thing is that even though Rava concluded in the Gemara that one is Yotzei with the Shofar of a conscrecated animal, the Rambam writes that this is only b'Di'eved, not l'Chatchilah. If so, however, then why does the Rambam imply that if one had taken a Neder not to benefit from the Shofar, he may blow with it even l'Chatchiah? The Chukas ha'Yom answers that it must be that we are more stringent with Hekdesh. Even though we say that "Mitzvos Lav Leihanos Nitnu," nevertheless we also say that ideally one should not use a Hekdesh item to perform the Mitzvah. In contrast, a Neder is lest severe than an animal belonging to Hekdesh, so one may use, even l'Chatchilah, the Shofar from which one has vowed not to benefit.

4) The Chukas ha'Yom now answers that this is why Tosfos here (59b) says that one may not use the Hekdesh ashes for sprinkling. Even though, if one did sprinkle with them, one would did not transgress Me'ilah, nevertheless we are Machmir with items belonging to the Beis ha'Mikdash and we say that you should not use them to perform Mitzvos with, in the same way that the Rambam says that l'Chatchilah one should not blow with the Shofar of a Korban Olah.

Kol Tuv,

Dovid Bloom

Here is a different answer, based on a Yesod of Rav Chaim Brisker.

1) In Chidushei Rav Chaim Solovetchik zt'l of Brisk, on the Rambam, Hilchos Me'ilah 8:1 (DH v'Nir'eh), he writes that the basis of the prohibition of "Me'ilah" is a Din of stealing from Hekdesh (this is why if, for example, somebody eats meat that belongs to the Beis ha'Mikdash, the amount that he has to eat in order to be liable to bring a Korban Me'ilah as atonement is not a k'Zayis but rather a Perutah (a financial, monetary value), because the prohibition is transgressed by stealing the property of Hekdesh, not because of the prohibition of eating Hekdesh).

2) He writes further (DH uv'Emes) that the primary liability of Me'ilah is not because the person derived benefit from the Beis ha'Mikdash, but rather because he stole from the Beis ha'Mikdash. In addition, Rav Chaim cites the Gemara in Me'ilah (18a) which states, "There is no Me'ilah other than 'changing.'" This means that when someone does something forbidden with the property of Hekdesh, it is considered that he has changed it from the purpose that it should have been used for, i.e. he has stolen it.

(See also Chidushei Rav Chaim on Shas (stencil), on Seder Kodshim, in the piece about "Me'ilah through a Shali'ach," page 218, DH v'Hineh b'Emes.)

3) According to the above understanding, we can now answer your question on Tosfos. Tosfos writes that it could not be that they would use ashes of Hekdesh to sprinkle the May Chatas on an individual in order to make him pure. It is true that when they use the ashes they are doing a Mitzvah and that Mitzvos Lav Leihanos Nitnu, so this is not considered that one is deriving benefit from the Beis ha'Mikdash. However, according to the above explanation of Rav Chaim, the problem about using Hekdesh items is not because one is deriving benefit from them, but because one is stealing them by using them for a purpose for which they are not intended. Therefore, if the ashes had been made into Hekdesh it would not be possible to use them to make an individual Tahor, because this is not the purpose of the property of Hekdesh and, consequently, it would be considered a "Shinuy" and would represent stealing from Hekdesh.

Dovid Bloom

According to the Olas Shlomo, there is no prohibition against deriving benefit from the ashes of Hekdesh, because "Mitzvos Lav Leihanos Nitnu."

The problem involved is a different one. When one uses the Hekdesh ashes to purify a private individual, it is considered that one is thereby destroying and wasting the property of Hekdesh. He compares this to what Tosfos in Zevachim (76b, DH

Log) writes, that if one pours Hekdesh oil on the toes of someone who is not a Metzora, this is equivalent to destroying the Hekdesh oil and is forbidden. Even though when one sprinkles the Chatas water this does not actually destroy the ashes, nevertheless the fact that these ashes have mixed with the water

means in practice that they can never be used again, which is whay the Olas Shlomo says that using the ashes to purify someone is considered as using Hekdesh property for non-Hekdesh purposes.

Kol Tuv,

Dovid Bloom