Rashi on the words “ויעש כן אהרן” “ exclaims “להגיד שבחו של אהרן שלא שינה” translated as Aaron didn’t change. The Sfas Emes elaborates Rashi’s words that not only in the actual act of lighting but in the feelings of passion and fervor for the mitzvah Aaron was always consistent. The question that comes to mind is how is it possible to be consistent on an every day level with feelings and passion?
To understand this lets explore. Rashi explains on the words “בהעלותך את הנר” “ that Aaron was bothered tremendously by not being involved in the חנוכת המזבח (the consecration and the initial sacrifices of the mishkan). He was consoled with the fact that he would be the one to light the candles. The question is Aaron was going to be the כהן גדול and be able to do many sacrifices in the future so why was he bothered by not being able to be first? Also why was he consoled with the specific act of lighting the candles?
Aaron witnessed the inauguration of the spiritual Mishkan and the karbonos that would impact the entire Klal Yisroel and future generations. Realizing the tremendous potential of the inaugural moment, he missed the ability to inspire Klal Yisroel spiritually and it bothered him tremendously. The way he was consoled was with the fact that he would have that same ability to inspire Klal Yisroel daily with a refreshed and renewed feeling as an inaugural moment.
When one understands that the impact of his mitzvah inspires and gives life in the spiritual world he can get to a level of Aaron and be consistent in his passion!