Parshat Chukat includes three commandments. All of these commandments deal with impurity through contact with a dead body. The first commandment is the requirement to secure and burn a red heifer – a parah adumah. The ashes of the parah are then retained for use in the purification process of a person who became defiled through contact with a dead body. The second commandment is the laws regarding defilement through contact with a dead body. The final commandment deals with the unique attribute of the mixture created from the ashes of the parah. Although these ashes are used in the process of purification, they also transmit impurity to those who process the parah.
In our passages Hashem communicates to Moshe and Aharon the first of the commandments and directs them to instruct Bnai Yisrael in this commandment. The instructions begin with the directive that the nation should take a red heifer that meets the requirements of the Torah. It must be completely red; it must be free of any blemish, and it must not have previously employed in any labor.
Maimonides explains that one of the many laws concerning the parah is that it should be purchased from the communal funds of the Bait HaMikdash. These communal funds are created through an annual tithe. Every male is required to contribute to the fund.
What if a person contributes a parah adumah? Can this contribution be accepted for the purpose of fulfilling the mitzvah of parah adumah? There is a general rule that would seem to address this issue. There are a number of sacrifices that must be offered by the nation. The animal used for the sacrifice must be collectively owned by Bnai Yisrael. In order to meet this requirement the animals used in these sacrifices are purchased from the Bait HaMikdash’s communal funds. However, if a person contributes an animal to the tzibur – to the national community – it may be accepted for and used as one of these communal sacrifices. Mishne La’Melech suggests that this principle also applies to the parah adumah. Maimonides does not intend to imply that there is an absolute requirement to purchase the parah with community funds. The parah must be owned by the tzibur. Purchasing the animal with community funds meets this requirement. However, the requirement is also met when a person donates the parah to the tzibur.
Others disagree. Aruch HaShulchan contends that the general principle that an animal donated to the tzibur may be used for communal sacrifices does not apply to the parah adumah. The parah adumah should be purchased from communal funds. An animal donated to the tzibur does not meet this requirement. Presumably, he maintains that this is Maimonides’ position. Maimonides’ ruling that the parah should be purchased from community funds is to be understood literally.
We can easily understand the position of Mishne LaMelech. According to his understanding, the requirement regarding the parah adumah is identical to the requirement for communal sacrifices. The animal must be owned by the tzibur. An animal donated to the tzibur is acceptable. But the position of the Aruch HaShulcan requires more careful analysis. Why is the parah adumah different from communal sacrifices? Why must the animal be secured through purchase with communal funds?
There is another interesting problem with Maimonides’ ruling. Maimonides rules that all communal sacrifices must belong to the tzibur. This is an absolute requirement. This requirement would seem to apply to the parah adumah. However, Maimonides, in discussing the requirement to purchase the animal from communal funds, does not express this requirement as an absolute requisite. Instead, he states that the animal should be purchased from communal funds. According to Aruch HaShulchan, this seems to imply that the animal should be purchased from communal funds but that an animal donated to the tzibur can be used. In other words, although the community is required to purchase the animal through the communal fund, if the animal is donated to the community it is acceptable. This raises a second question. Why is the requirement to purchase the animal with communal funds not an absolute requisite? If the animal should be purchased with communal funds, why is a donated animal acceptable?
Rav Naftali Tzvi Yehudah Berlin – Netziv – provides an insight that helps answer these questions. He agrees with Aruch HaShulcan that the tzibur is required to purchase the parah from communal funds. He explains that the source for this requirement is in the midrash Sifrai. Sifrai explains that Moshe is commanded to instruct Bnai Yisrael to “take” a parah adumah from which the required ashes will be created. Sifrai explains that this term is the source for the requirement to purchase the parah from communal funds. Netziv comments that this derivation clearly adjoins us to purchase the parah with communal funds rather than accepted a donated parah. If the parah is donated, then the tzibur has failed to fulfill the obligation of “taking” a parah.
Apparently, according to Netziv, the mitzvah of parah adumah does not only describe the process for creating the ashes of the parah adumah; the mitzvah also establishes an obligation upon the nation to proactively assure that these ashes are available for those who must purify themselves from defilement through contact with a dead body. The requirement that the nation take a proactive role dictates that the tzibur purchase the parah from communal funds. In other words, the ashes can be created from a donated parah and these ashes can be effectively used in the purification process. However, if the nation does not purchase the parah, it has not fulfilled its obligation to proactively assure that this instrument for purification is available.
With this insight, we can understand Aruch HaShulchan’s interpretation of Maimonides. According to Aruch HaShulchan, the parah adumah cannot be compared to other communal sacrifices. The mitzvah of parah adumah includes an element that is not relevant to communal sacrifices. The nation does not have an obligation to proactively secure these sacrifices. In contrast, the nation does have an obligation to proactively assure that the means of purification from defilement through contact with a dead body are available.
We can also understand why failure to meet this requirement does not affect the efficacy of the ashes. The ashes of a parah donated to the tzibur are effective. This parah is owned by the tzibur and consequently, its ashes are completely effective. However, when the parah is donated the tzibur has failed to fulfill its obligation to proactively secure and provide the means of purification.
 Rabbaynu Moshe ben Maimon (Rambam / Maimonides) Sefer HaMitzvot, Mitzvat Aseh 113.
 Rabbaynu Moshe ben Maimon (Rambam / Maimonides) Sefer HaMitzvot, Mitzvat Aseh 107.
 Rabbaynu Moshe ben Maimon (Rambam / Maimonides) Sefer HaMitzvot, Mitzvat Aseh 108.
 Rabbaynu Moshe ben Maimon (Rambam / Maimonides) Mishne Torah, Hilchot Parah adumah 1:1.
 Rav Yehuda Rosanes, Mishne La’Melech, Hilchot Parah adumah 1:1.
 Rav Yechiel Michal HaLeyve Epstein, Aruch HaShulchan HaAtede, Hilchot Parah adumah 52:8-10.
 Rabbaynu Moshe ben Maimon (Rambam / Maimonides) Mishne Torah, Hilchot Klai Mikdash 8:7.
 Rav Yosef Babad, Minchat Chinuch, Mitzvah 397, note 2.
 Rav Naftali Tzvi Yehuda Berlin (Netziv), Commentary Emek HaNetziv on Sifrai, Parshat Chukat, chapter 1.