When Hakadosh Baruch Hu instructed Moshe Rabbeinu to take the Bnei Yisrael out of Egypt, Moshe was concerned that his older brother Aharon would resent the fact that Moshe was the one who was ascending to greatness. Hashem assured Moshe to the contrary, “He is going out to you and will see you and rejoice in his heart.”
The Midrash relates that if Aharon would have known that the Torah would state this about him, he would have greeted Moshe with music and dancing.
At first glance, this Chazal appears perplexing. Aharon Hakohen was on an extraordinarily lofty level. Why would whether or not the Torah wrote about him affect his decision to greet his brother with music? Why, indeed, did he not do so?
Hagaon Harav Elazar Shach, zt”l, suggested that Aharon Hakohen was continually analyzing all his actions to ensure that they were free of any spiritual imperfection. When Aharon joyfully went to greet Moshe, he did so without any feelings of jealousy. But Aharon suspected that perhaps, in reality, he wasn’t totally free of this most negative trait. Since he wasn’t 100-percent certain that he harbored no trace of jealousy, he feared that perhaps the use of music and dancing wouldn’t accurately reflect what he felt in his heart. Unwilling to perform an action that wasn’t totally true, Aharon chose not to greet his brother with music.
Had Aharon known that the Torah would bear witness that, in fact, his heart was filled with happiness and totally free of jealousy, he would gone out with music and dancing.
Harav Shach used this concept to teach his talmidim that a person must examine his actions to ensure that they are truthful and that they accurately reflect his real feelings.
When the same question was asked of Hagaon Harav Yosef Sholom Elyashiv, zt”l, he gave a different explanation: Certainly Aharon Hakohen knew himself well and was confident that he didn’t hold a trace of jealousy in his heart. Well aware of the greatness of his younger brother, Aharon would have gone to greet his brother with music and dancing. What concerned him was what the Torah says about such a scenario. He knew that according to halachah, an older brother has priority over a younger one — even if the younger one is greater. Aharon was unsure whether it was appropriate to show such deference to a younger brother. Had he known that the Torah would state, “he will see you and rejoice in his heart,” and therefore there is no issue of priority in such a case, he would have greeted him with music and dancing. (Adapted from the sefer Gedolah Shimusha)
A third explanation also seeks to answer a related question: As the Rashi states on next week’s parashah, the Torah sometimes names Aharon before Moshe and sometimes Moshe before Aharon, to teach that they are of equal significance. Why indeed did Hashem choose to send Moshe and not Aharon?
The Gemara (Taanis 25b) tells of the time there was a drought and Rabi Eliezer ben Horkenus served as shaliach tzibbur. He was mispallel the special tefillah with 24 brachos that are to be recited in such a case, but was not answered. Then Rabi Akiva served as shaliach tzibbur and said Avinu Malkeinu — “Our Father, our King, we have no King but You! Our Father, our King, for Your sake have compassion on us!”
The rains then began to fall, and the Rabbanim started murmuring that since Rabi Akiva’s tefillah was answered and not that of Rabi Eliezer, this meant that Rabi Akiva was greater.
A bas kol was then heard: “It is not because this one is greater than the other, but because he [Rabi Akiva] is ma’avir al middosov.”
While many explain the words ma’avir al middosov to mean a forgiving person, they can also be understood to mean someone who works to rectify his character traits. Rabi Eliezer was born with very lofty middos; Rabi Akiva had to work hard on his middos, and therefore his tefillah was answered.
In a similar vein, Aharon Hakohen was born with perfect middos. In contrast, Moshe Rabbeinu was born with every evil character trait imaginable, and with incredible strength and determination worked on himself to totally subjugate those traits and totally eradicate the evil within him.
Therefore, though they were equal in many ways, Moshe was chosen to take the Bnei Yisrael out of Egypt and lead them for 40 years.
To Aharon, born free of any negative traits, the very concept of jealousy was foreign to him; it didn’t occur to him that anyone else would think that he might be jealous, and therefore there would be a need to show his brother that he wasn’t jealous by greeting him with music. But Moshe Rabbeinu, who had been born with negative traits and rectified them, did know about it, and feared that his brother would have some sort of resentment — as would be expected of most other mortals in such a situation. Had Aharon known that Hashem saw it necessary to assure Moshe Rabbeinu that Aharon was rejoicing in his heart, he would have greeted him with music and dancing to show his happiness as well. (Adapted from a teaching by Harav Hillel, the Rav of Suvalk, zt”l, as quoted in the sefer Koheles Yitzchak.)