Aharon was ashamed and afraid to approach [due to the sin of the Golden Calf[1]]. Moshe said to him: Why are you ashamed? lekach nivcharta  [It was] for this that you were chosen

In two words, Moshe has turned Aharon around!

It is hard to grasp why. Was Aharon in need of a simple pep talk? [Aharon - YOU can do it!!]. We fail to see how Moshe has removed Aharon's sense of embarrassment? If indeed Aharon's reticence stems from his role in Golden Calf episode, how do Moshe's words change anything?

Many struggle to explain the change. Two Chassidic explanations penetrate a Litvishe soul:

Both veer from simply interpreting lekach prospectively (for this task), and opt for the causative; Lekach - It is for this very reason that you have been chosen.  

1. Your feeling of fear and embarrassment is why you have been chosen - for the greatest sacrifice to Hashem is the broken heart[2]. Aharon, had you felt a sense of confidence and entitlement, you would not be worthy of being the Kohen Gadol of Klal Yisrael. [Reb Elimelech of Lizhensk, Besht al HaTorah]

R, Yitzchak Blazer [later known as R. Itzele Peterburger] was pushed by R. Yisrael Salanter to St. Petersburg to accept the major Rabbinic position in Czarist Russia. To put it mildly, St. Petersburg was not Vilna and R. Itzele was therefore extremely hesitant and protested that as a young man, he did not feel ready for the position. R. Yisrael responded: "and whom should I recommend - someone who feels that he is ready?"

The reluctant leader walks in without hubris and possesses a sense of authentic humility - critical traits of real leadership that requires one to quickly recognize one's mistakes and to regroup. How many lives and wars have been lost by the ego's blinding light!  

2. The source of your embarrassment is why you [not I] have been chosen. [Maor V'shemesh]

When dissecting why Shaul ultimately failed where David succeeded, the Rabbis make a penetrating comment: [Yoma 22b]

Rab Judah said in the name of Samuel: Why did the kingdom of Saul not endure? Because no reproach rested on him, for R. Johanan had said in the name of R. Simeon b. Jehozadak: One should not appoint any one administrator of a community, unless he carries a basket of vermin on his back, so that if he became arrogant, one could tell him: Turn around!

Precisely because Shaul was so past-perfect, he had no coping mechanism to handle failure; thus he was unable to properly integrate Shmuel's rebuke. David, who came from a controversial union[3] and withstood much personal attack ultimately accepts Natan's rebuke [in the Batsheva story] and engages in a swift and full teshuva.

Consider: When our parsha begins, it is the eight day. For seven days, Moshe walks in and out of the Mishkan, performing as the Kohen Gadol and is unable to evince the Shechina. In rabbinic terminology, Moshe wore a white cloak with no stains. On some level, Klal Yisrae's shechina requires one who understands and can relate to their imperfections

Aharon, whose capacity as Kohen Galdol is to represent and understand his community, [particularly in the context of atonement] understood from whence they came, precisely because of his failure^.[4],[5]

Thus Moshe says to Aharon

You, not I have been chosen, because your experience allows you to relate to Klal Yisrael with greater understanding and humility.

As we become real with our shortcomings, may they become platforms for our growth and indeed greatness

Good Shabbos - Asher Brander

A freilichen, a kasheren, a zeisen Pesach - L'shana Haba'ah b'yerushalayim - Good Shabbos