bring certain korbanot (sacrifices) on behalf of himself and the nation. Chazal tell us that he was hesitant when he saw the calf to be brought, as it reminded him of the sin of the Golden Calf, in which he played a failed role. Moshe said to him: "Why are you embarrassed? For this you were chosen." This week, when we also read of the removal of impurity by the red heifer, mother to the calf, let us investigate the retrospective outlook on that sin and Aharon's transcendence of the obstacles it placed before him.
The Netivot Shalom asks a simple, strong question: is it surprising for Aharon to have been embarrassed, considering his not small part in the enormous sin? The gemara (Avoda Zara 4b) states that Bnei Yisrael sinned in order to teach the power of repentance. In other words, the sin of the Golden Calf was Divinely ordained and was not a product of free choice. The Netivot Shalom posits that the preventable sin, which justified the punishment, was not the making of the calf but the fact that they rejoiced thereafter and were not reviled by the sin. Since Aharon did not take part in the rejoicing, he had not sinned with the calf itself and needed not be embarrassed by it.
He goes on to cite the statement of Rav Chaim Vital, based on the above statement, that Aharon was chosen specifically because he was embarrassed. While this is a sign of humility, the Torah tells us that Moshe was the most humble person, so why did Aharon, not Moshe, receive the honor to serve in the Mishkan? The Netivot Shalom answers based on the following analysis. A person may be humble before Hashem because he is fully aware of His glory and palpably feels his inadequacy in relation to Him or due to a feeling of internal inadequacy which lowers one's self-image. Moshe, the greatest prophet ever, possessed the first type of humility. Aharon, who took fuller responsibility for his part in the Golden Calf than he needed to, lowered his self-image to the point of being broken with remorse. A "broken spirit" is the key to bringing korbanot to Hashem, and especially regarding sin offerings, making Aharon the optimal kohen.
One can add that Aharon's humility in this regard has another dimension. The nation, on whatever level, sinned and needed atonement. Aharon maximized his responsibility in their need for atonement. So too, a kohen is exposed to sinners who need to take responsibility. As a leader in the nation, charged among other things with education and atonement, the kohen should feel a part in the collective sin. He should work with dedication and humility, not to gloat over the sinner, but to lead him back, whether it be with the ashes of the red heifer, the sin offering, or words of advice and encouragement that help one return to the proper path.