Musar zu Schemot 3:11

We also see that Moses was very humble, saying "who am I that I should go to Pharaoh." He had preferred that this privilege be accorded to his older brother Aaron (Exodus 3,11). How much humility must the likes of us practice when even a great man such as Moses wanted to defer to his brother!

Aaron also thought that the elevation of Moses to a position of redeemer was not necessary, but only an act of kindness on the part of G–d who imparts some of His own honour to those who fear and revere Him. He did not think that there was any practical significance in this, seeing redemption would be brought about by G–d Himself. Moses himself had thought along similar lines when he declined the mission to become the official leader of the Jewish people. His query: מי אנכי אשר אלך, "Who am I that I should go,” reflected his thinking (Exodus 3,11). The Midrash already re-phrases Moses' question as מי אני, "who am I, seeing that the one called אנכי is going to redeem the Jewish people!" Whereas Moses was correct in his basic assumption, G–d wanted to lend glamour to Moses, as He said later: ראה נתתיך אלהים לפרעה, "See here, I have made you a deity as far as Pharaoh is concerned." The greatness of Moses' honour can be measured by the fact that it was he who was chosen by G–d to hand the Torah to the Jewish people; he was told at the time that his mission would be considered a success when the Jewish people would accept the Torah at Mount Sinai (Chorev) (cf. Exodus 3,12). Aaron was unaware of these details at the time; this is why he thought that he had behaved in an exemplary fashion by not begrudging Moses his new status. The Midrash then was quite correct when it said that had Aaron been aware that he was to receive credit for his attitude, and that it was only Moses who could be the intermediary in accelerating redemption, he would have gone to meet his brother with drums and dances of joy just as we found Miriam doing after the miraculous rescue of the Jewish people (Exodus 15, 20).