In Parashat VaEira, the Torah tells us, “Hu Aharon UMoshe Asher Amar Hashem Lahem Hotziu Et Bnei Yisrael MeiEretz Mitzrayim Al Tzivotam Heim HaMedaberim El Paroh Melech Mitzrayim LeHotzi Et Bnei Yisrael MiMitzrayim Hu Moshe VeAharon,” “These are the [same] Aharon and Moshe to whom Hashem said: 'Bring out the Children of Israel from the land of Egypt according to their hosts.' These are the ones that spoke to Paroh, king of Egypt, to bring out the children of Israel from Egypt. These are the [same] Moshe and Aharon” (Shemot 6:26-27).
Why does the Torah say Aharon’s name first in Pasuk 26 and second in Pasuk 27? Rashi answers that Moshe and Aharon were equal, so their names are interchangeable. But, as many Rishonim, including the Rambam note, Moshe was the greatest prophet of all time. How could Moshe and Aharon be equal?
Rav Aharon Soloveitchik answers based on a Midrash that states, “Kindness and truth met, and righteousness and peace kissed.” The Midrash elaborates that kindness and peace refer to Aharon, while truth and righteousness denote Moshe, as each pair of characteristics was the most noteworthy for each person.
Based on this, we can understand Rashi. The contradiction in the Pesukim does not imply that Moshe and Aharon were equal, but rather that their primary attributes in fact were quite interrelated, as truth and righteousness cannot function without remaining in harmony with kindness and peace. Moshe makes it quite clear that he felt himself unable to deal with both Paroh and Bnei Yisrael single-handedly (6:10-12), whereupon Hashem speaks to both Aharon and Moshe, telling them to confront, as a unit, both Paroh and Bnei Yisrael (6:13).
Thus, we see that Moshe and Aharon were actually equal in the amount that each contributed during the various interactions with Paroh and Bnei Yisrael. From here we learn that one needs to employ both truth, like Moshe, and peaceful and kind mannerisms, like Aharon.