The Torah does not really distinguish Aaron. He accompanies Moses all the time as if hiding in his shadow. Moses acts as a connector between the Creator and the people, and Aaron stands beside him as his assistant and brother.
The role of Aaron is not very clear from the story. But exactly because it is not understood, it is apparently more hidden. It means it is closer to a person, to you and me in relation to our work.
Aaron prepares the vessels, the connection of people with the Creator. Moses comes from above, and Aaron comes from below, from the people, from all the properties of a person, the entire group, the ten in relation to the Creator. And therefore, the role of Aaron does not stand out so much because one must add his work to it. Moses acts as the representative of the Creator before the people, and Aaron is the representative of the people before the Creator.
If I am under the rule of the Creator and there is none else besides Him, then I must always be content in any state. And if I am dissatisfied with something, then it means that I am separated from the Creator. Therefore, I need to return to the connection with Him, and a sign that I have this connection will be my joy in any state, whatever it is.
The quality of Aaron is the most important quality in a person. The qualities of Abraham, Isaac, Jacob, and Moses are just preparation from above. And the quality of Aaron is our work from below, which we realize when we achieve faith above reason, that is, mercy (Hesed), which is above all, bestowal, which is above any desire to receive pleasure.
To study the qualities of Aaron means to accept him as a guest in our Sukkah. We want his property to build our soul, the right connection between us. To clothe the Hesed property on all of your inner properties called “the people of Israel” means to do the work of Aaron—to take over his property on yourself, on all your desires to receive pleasure.
From the Daily Kabbalah Lesson 10/7/20, “Sukkot“