The opening section of Parashat Hukat introduces and discusses the Misva of Para Aduma, a special cow which was required for the process of purifying people or utensils who had become Tameh (impure) through contact with a human corpse. The cow would be burned, and its ashes would be mixed with water. This water would be sprinkled on people and objects that had become impure, and they would then become pure once again. Surprisingly, the Shulhan Aruch (Orah Haim 685:7) brings a view (which appears first in Tosafot in Masechet Berachot 13a) that the annual reading of this section constitutes a Torah obligation. We read this section each year not only this Shabbat as part of the yearly Torah reading cycle, but also on a special Shabbat in between Purim and Pesach, which we call “Shabbat Para.” According to this view cited by the Shulhan Aruch, reading this Parasha each year is required on the level of Torah law, as opposed to virtually all other Torah readings, which are required Mi’de’rabbanan (by force of the Rabbis’ enactment). The question naturally arises as to the source and reason of this requirement. There is no Biblical obligation to read about other Misvot. Why – and where – does the Torah require reading about the Para Aduma? Rav Yaakov Kamenetsky (1891-1986), in his Emet La’Yaakov (Parashat Ekeb) answers that the source of this obligation is a verse in Parashat Ekeb (Debarim 9:7), where the Torah commands us to remember “how you angered Hashem your G-d in the wilderness.” The Malbim (Rav Meir Leibush Weiser, 1809-1879), in his work Arsot Ha’haim, claims that this refers to the sin of the golden calf, but Rav Kamenetsky disagrees, noting that the golden calf is mentioned separately in the next verse (“U’b’Horeb Hiksaftem Et Hashem”). Therefore, Rav Kamenetsky suggests that this command refers to the events that transpired in Mara, shortly after Beneh Yisrael crossed the sea. As we read in Parashat Beshalah (Shemot 15:22-26), Beneh Yisrael found themselves without water until finally arriving in Mara, where they encountered a body of water, but the water was bitter and foul-tasting. They angrily complained to Moshe, demanding water. G-d responded by commanding Moshe to cast a piece of wood into the water, whereupon it miraculously transformed into sweet drinking water. After this miracle, G-d had Moshe present to the people “Hok U’mishpat,” which Rashi explains as referring to several Misvot, including the Misva of Para Aduma. Thus, Rav Kamenetsky writes, by reading the Misva of Para Aduma, which was first presented at Mara, we fulfill the Biblical command to remember Beneh Yisrael’s angry complaints at Mara, where they challenged Moshe rather than placing their trust in Hashem. Rav Kamenetsky explains further the connection between the Para Aduma and Beneh Yisrael’s sin at Mara. The Para Aduma shows that by following Hashem’s rules, an impure person can be transformed, and regain his purity. We do not and cannot understand how sprinkling the Para Aduma waters brings a person purity, but Hashem said that this is how purity is regained. Likewise, at Mara, Hashem determined that a piece of wood should transform bitter water into sweet water. According to natural law, there is no reason whatsoever for why this should happen. Wood does not change foul-tasting water into fresh drinking water. But Hashem has he power to change any “bitter” situation into “sweetness,” in ways which we can never expect or understand. This was the people’s mistake at Mara – failing to recognize that the bitter water can be made sweet. The Torah commands us to remember this incident in order that we strengthen our Emuna, our faith in G-d’s unlimited ability to “sweeten” any form of “bitterness,” so that instead of complaining and bemoaning our circumstances, like our ancestors did in Mara, we turn to Hashem and ask for help. We fulfill this Misva through the reading of Parashat Para, which reminds us that Hashem can bring purity to the impure in ways which we do not understand. Just as an impure person can regain his purity through the mysterious process of the Para Aduma waters, so can any “bitter” situation be transformed to “sweetness” through G-d’s unlimited power and capabilities.