After the miraculous destruction of Korach and his followers, Hashem instructs Moshe to demonstrate for all time His choice of Aharon as kohein gadol (high priest) and his descendants as kohanim (priests). After the leaders of the tribes along with Aharon provided their staffs which were placed in the Kodesh haKodoshim (holy of holies), Aaron's staff miraculously blooms and produces fruit while the others remain the same. The Torah describes this event in the following manner: "And it (Aaron's rod) brought forth blossoms, and sprouted buds, and almonds ripened (17:23)." Da'as Z'keinim miBa'alei HaTosfos comment, basing themselves on a Talmudic passage in Yoma (52b), that at the same time that almonds were produced on one side of the staff, blossoms remained on the other side. What might be the symbolism behind this dual-natured blossoming of Aaron's rod?
The root of Korach's rebellion as stated by Rashi, Ramban, and expanded upon at length by R. Soloveitchik zt"l was a private jealousy of the positions of leadership of Aharon, Elitzaphan (the leader of the Levitic family of K'hos) and Moshe. In order to advance his private agenda, Korach develops a popular philosophy questioning the very need for leadership in the hope of rallying the masses for the ultimate, hypocritical goal of achieving his personal desire, attaining a leadership role for himself. His jealousy is rooted in the pursuit of the glorious aspects of leadership, as opposed to a desire for greater accomplishment. Moshe Rabbeinu, by stark contrast, in Parshas B'ha'alos'cha acts in the exact opposite manner. When Eldad and Meidad prophesy the end of Moshe's leadership, instead of agreeing to Yehoshua's request to stop them, Moshe expresses his fervent wish: "umi yitein kol 'am Hashem n'vi'im" -- may the entire nation merit to be prophets, without concern for the loss of his personal honor. A true leader views his role not as a means to individual aggrandizement but as a forum for immense service to the community which he leads, that which would not be possible for a private individual. Indeed, Moshe Rabbeinu and his brother Aharon HaKohein are never satisfied by their past missions but constantly strive for additional achievements for the sake of G-d and Klal Yisrael. The Talmud Sotah (14a) records a conversation which takes place between Hashem and Moshe as the latter pleads to enter the Promised Land. "Do you desire to fulfill the mitzvos which only apply in Eretz Yisrael? I will view it as if you already performed them," the Almighty tells Moshe. Now, Moshe had certainly spent his life in the performance of the Divine commandments; why was it so crucial for him to fulfill the additional mitzvos hat'luyot ba'aretz (Israel-bound mitzvot)? A tzaddik is never satisfied with his past achievements; he always strives for more. The Gemara Makkos (10a) applies to Moshe the verse in Koheles : "Oheiv kesef lo yisba kesef" which is homiletically translated as, "one who loves mitzvot will never be satiated by them." (See Purim: the Holiday of Giving Section I by mori v'Rabi, Rav Mordechai Willig for a further elaboration on this theme.)
R. Moshe Eisemann once commented on the life of Boaz, one of the heroes in the narrative of Ruth. The Midrash identifies Boaz with the Judge Ivtzan mentioned in Shoftim (12:8-10), who fathers 30 sons and 30 daughters. Yalkut Shimoni (Shoftim 68) relates that all of Boaz's children died during his lifetime leaving him childless in his old age. Then, toward the end of his life, the aging Boaz, marries Ruth, and they have a child who is the ancestor of King David and eventually the Melech HaMashiach! Boaz could certainly have taken the "easy route" and given up after living such a tragic life. Instead, he followed the directive of Kohelet "Baboker z'ra et zar'echa, v'la'erev 'al tanach yadecha ki 'eincha yodei'a eize yichshar hazeh 'o zeh (11:6)" -- "in the morning plant your seed, and in the evening do not stay your hand, for you do not know which (accomplishment) will be successful." Everyone in their life has their "Ivtzan" stage -- time periods when their efforts seemingly meet no success. But one cannot be discouraged by previous failures; one must constantly attempt new achievements until one finds one's "Boaz" stage, and even then to strive for ever greater accomplishments.
Aharon HaKohein's most prominent responsibility was the lighting of the menorah (see B'ha'alos'cha 8:2-3). Interestingly, the actual lighting of the menorah does not require a Kohein and can be performed by a Yisrael as well (Yad HaChazaka Hilchos Bi'at Mikdash 1:7). The hatavas hamenorah, the evening cleaning of the menorah in preparation for the lighting, does need a kohein. R. Noach Isaac Oelbaum once explained this halacha in a manner similar to the above-mentioned theme. The greater achievement is the ability to "clean out" former, failed attempts and start anew, never to fall into despair and never to be satisfied with the past achievements. This is what Aharon haKohein, once again in contrast to Korach, teaches us. Leadership is a means for 'avodas Hashem, Divine service, not personal glory. The very word kohein, in its verb form l'chahein, means "to serve."
This is perhaps the deeper significance of the double-blossomed staff. Even after one sees "fruits" for his efforts, one should constantly strive to "blossom" again with new missions, new mitzvot, new venues for increasing the Glory of G-d in this world. It is this lesson that the lives of Moshe and Aharon and of all true Jewish leaders teach us, and it is this model that we must follow.