A number of questions concerning the text of this pasuk are appropriate. First, Bnei Yisrael did not travel from Beeros to Moserah. On the contrary, Moserah preceded Beeros in their list of encampments. Rashi cites the Midrash which explains that this was actually part of Moshe’s rebuke to Bnei Yisrael. Aharon’s death at Har Hahar effected the departure of the clouds of glory, which had previously protected them in the desert. This change caused great consternation among many of the people. In the ensuing confusion, the people attempted to return to Egypt. After traveling back eight encampments to Moserah they fought with the Leviim, which resulted in many tragic deaths. They ultimately returned brokenhearted and dejected to their original position. While in Moserah, however, they mourned and eulogized Aharon, for they realized that this entire debacle was caused by Aharon’s death. It was subsequently viewed as if Aharon had died in Moserah. The Yerushalmi in Sotah states that this renewed mourning for Aharon was preempted by the realization that they had not paid proper tribute to Aharon’s memory.
The Be’er Yosef questions this idea. How can we imagine that Aharon, who was so loved by each member of Klal Yisrael, was not appropriately eulogized and mourned? Aharon’s love for each individual Jew was evident in every facet of his behavior, and this love was powerfully reciprocated. He answers that Aharon was certainly beloved by all and was surely properly eulogized. His moral character and spiritual qualities would be sorely missed. His demise would have an everlasting effect on every Jew. The mistake, however, lay in the focus of their eulogy and their misguided perception of Aharon’s current value to Am Yisrael. They mourned him for his greatness as a leader during their tenure in Egypt and sojourn in the desert. Although they acknowledged his protective qualities in the past, they felt they were now out of danger and no longer needed a leader of his caliber. They also thought that at his advanced age he no longer provided the protective influence for them. They confirmed his sustenance of the past, but did not reflect on his maintenance of the present.
Hashem educated Bnei Yisrael by removing the clouds of glory immediately following Aharon’s death. Afterwards, when they battled the Canaanites, many of them attempted to return to Egypt until the Leviim overcame them. When brother fought against brother and thousands perished, their eyes finally opened. They perceived the great loss that had befallen them: Aharon had died! They now realized that these tragic circumstances were the result of not appropriately appreciating Aharon. This teaches us that we should forever be cognizant that the presence of our Torah sages provide a constant protective influence over all of us.