(א) בָּרוּךְ אַתָּה יְהֹוָה אֱלֹהֵֽינוּ מֶֽלֶךְ הָעוֹלָם אֲשֶׁר קִדְּ֒שָֽׁנוּ בְּמִצְוֹתָיו וְצִוָּנוּ לַעֲסֹק בְּדִבְרֵי תוֹרָה:
(1) Blessed are You, Adonoy our God, Ruler of the Universe, Who sanctified us with commandments and commanded us to be engrossed in the words of Torah.
Some time after that, when Moses had grown up, he went out to his kinsfolk and witnessed their labors. He saw an Egyptian beating a Hebrew, one of his kinsmen. He turned this way and that and, seeing no one about, he struck down the Egyptian and hid him in the sand. When he went out the next day, he found two Hebrews fighting; so he said to the offender, “Why do you strike your fellow?” He retorted, “Who made you chief and ruler over us? Do you mean to kill me as you killed the Egyptian?” Moses was frightened, and thought: Then the matter is known!
(9) Now the cry of the Israelites has reached Me; moreover, I have seen how the Egyptians oppress them. (10) Come, therefore, I will send you to Pharaoh, and you shall free My people, the Israelites, from Egypt.” (11) But Moses said to God, “Who am I that I should go to Pharaoh and free the Israelites from Egypt?” (12) And They said, “I will be with you; that shall be your sign that it was I who sent you. And when you have freed the people from Egypt, you shall worship God at this mountain.”
By saying: "that shall be your sign" G'd may also have indicated to Moses that the very fact that he did not consider himself as adequate for the task was the factor which had made G'd choose him. G'd needed a humble person, not an arrogant one. The reference to that mountain which was not a high mountain was to confirm that G'd preferred the humble and the modest to the high and mighty, and therefore arrogant. G'd could have chosen Mount Hermon as the site for the revelation; instead He chose Mount Sinai.
בהוציאך את העם ממצרים תעבדון את האלוקים על ההר הזה.. "when you bring bring the people out of Egypt, you will worship God on this mountain," even though they are not worthy of redemption at this time, but they are worthy of serving Hashem at this mountain when you take them out from among these professional sinners.
Rabbi Jonathan Sacks, "Who Am I?", https://rabbisacks.org/i-shemot-5777/
So when Moses asks, “Who am I?” it is not just that he feels himself unworthy. He feels himself uninvolved. He may have been Jewish by birth, but he had not suffered the fate of his people. He had not grown up as a Jew. He had not lived among Jews. He had good reason to doubt that the Israelites would even recognise him as one of them. How, then, could he become their leader? More penetratingly, why should he even think of becoming their leader? Their fate was not his. He was not part of it. He was not responsible for it. He did not suffer from it. He was not implicated in it.
What is more, the one time he had actually tried to intervene in their affairs – he killed an Egyptian taskmaster who had killed an Israelite slave, and the next day tried to stop two Israelites from fighting one another – his intervention was not welcomed. “Who made you ruler and judge over us?” they said to him. These are the first recorded words of an Israelite to Moses. He had not yet dreamed of being a leader and already his leadership was being challenged.
But he said, “Please, Hashem, make someone else Your agent.” Hashem became angry with Moses, and They said, “There is your brother Aaron the Levite. He, I know, speaks readily. Even now he is setting out to meet you, and he will be happy to see you.
Rachel Farbiarz, "How Aaron Helped Moses Overcome His Feelings of Inadequacy", https://www.myjewishlearning.com/article/lost-in-translation/
Aaron’s role as mediator was critical to the success of Moses’ leadership. Aaron’s translation not only smoothed away his brother’s stutterings, but also bridged a vast existential difference that stood between Moses and the slaves whom he was charged with liberating.
Moses, raised as the son of Pharaoh’s daughter, grew up in privilege. He had not been beaten for stumbling over his own exhaustion. His mind had not been numbed by the monotonous horror of slavery. Moses could certainly feel righteous rage for the bitterness of the Hebrews’ servitude, but their burdens had never been his. Their pain was not his desperation. He had simply never been a slave.
Aaron, by contrast, was not raised in Pharaoh’s palace: He was raised as a slave, among a family and community of slaves.
The partnership between Moses and Aaron helps us understand that in a situation of such disparity we cannot work alone, but must work together with the communities whom we seek to help.