The Torah in Parashat Masei briefly recounts the death of Aharon, informing us that he died at the age of 123 (33:38).
Aharon’s age at his death is mentioned by the Rambam in a surprising context – amidst his discussion of the laws of hallel, in Hilkhot Chanukah (3:12). The Rambam there describes how the congregational hallel used to be recited, telling that the chazan recited the entire hallel aloud, and at various points the congregation responded, “Halleluy-a.” These responses, the Rambam adds, numbered 123, and he adds, “siman lahem shenotav shel Aharon” – this number corresponds to the numbers of years Aharon lived. This association between the responses during hallel and the years of Aharon’s life is based on several earlier sources, including Masekhet Sofrim (chapter 16) and the Talmud Yerushalmi (Masekhet Shabbat, chapter 16).
What connection might there be between hallel and Aharon?
Rav Elimelech Meller, in the introduction to his Shai La-melekh, suggests that the answer to this question lies in Aharon’s “ayin tova” – the way he looked positively and favorably upon all people, as Chazal describe. He is famously depicted as “a lover of peace and pursuer of peace” who “loved people” (Avot 1:12). And, Chazal tell that when Moshe was appointed leader over Benei Yisrael, he was concerned that his older brother, Aharon, might feel slighted, but in truth, Aharon rejoiced over Moshe’s appointment. Aharon was somebody who focused on the positive aspects of all people, saw what to admire in them, and genuinely wished them well. He harbored no feelings of resentment, jealousy or grievance, and he thereby avoided conflict and hostility.
It is in this sense, Rav Meller suggests, that Aharon is associated with the recitation of hallel. In order to give praise to God, we must view our lives and the world with an “ayin tova.” We must look through the troubles and sorrow to find, and focus our attention on, all that for which we ought to feel grateful. Hallel is about gratitude, and gratitude requires a positive outlook. And thus Chazal drew our attention in the context of hallel to the example of Aharon, who looked kindly upon all people, instructing us to view the world with optimism and positivity, so we will then be moved to give praise to the Almighty with sincere emotion and joy.