The passuk states ההר הטוב הזה והלבנון this good mountain and the tree of Levanon. Rashi explains “this good mountain” refers to Yerushalayim, and “the Levanon,” both Onkelos and Rashi explain, refers to the Bais HaMikdash. What does it mean that Yerushalayim is referred to as “the mountain,” and the Bais HaMikdash as “Levanon”?
The Maharal explains a mountain is part of the land, however with its height and elevation it is separated to be above all other land. So too Yerushalayim was part of the land, but was above all other land. The Bais HaMikdash was on top of the mountain of Yerushalayim and is compared to Levanon, tall trees. Trees are not considered part of the land, rather they are on top of the mountains extending above the ground, and are separated from the ground. So too the Bais HaMikdash was separated from the entire world with its kedusha.
The Gemara explains that the Bais HaMikdash is called Levanon which means white, since it whitened the sins of Yisrael. The Maharal explains when a person sins he strays after his physical mundane nature. The Bais HaMikdash is a place which is separated from the ground and its physicality, therefore it is able to atone and whiten a person’s sin. When people will pass through the Mikdash which is holy, above physical mundane nature, sin will be removed from the person.
Why is the Bais HaMikdosh called Levanon, and not the resting place of the Shechinah? What is unique about whitening sins that the Bais HaMikdash is called after that? Similarly, we find by Dayeinu that we mention many things for which we have to thank Hashem, and the list ends with ולבנות את בית הבחירה לכפר על כל עונותינו and to build the Bais HaMikdash in order to atone for all of our sins. Why is atoning sins so significant that this is given as the reason for the building of the Bais HaMikdash?
Rav Pesach Miller answered: Avraham Avinu asked Hashem, “What will be if Yisrael will sin before You, will You destroy them like the dor hamabul and dor haflaga? Hashem said, “no, I won’t.” Avraham asked, “במה אדע with what can I know?” Hashem answered, “the korbanos will atone.” Since we bring korbanos we have the ability to become pure, and the world will not come to an end, it will be able to continue to exist. The purpose of the Bais HaMikdash was to bring korbanos to atone for our sins, and keep the existence of Klal Yisrael.
Rav Lisman gave another answer that Chazal say “there is no person who does only good and doesn’t sin.” A person constantly has challenges and will definitely fall. When a person falls and sins, he darkens his soul and distances himself from Hashem. The Maharal adds that something dark does not shine brightly. The Bais HaMikdash is called Levanon since it whitened and brought a shine back to a person by atoning for his sins.
May Hashem rebuild the Bais HaMikdash and bring us closer to Him by whitening our sins!