Source: Bnei Yisaschar - Revach.net
The Arizal says that each month represents a part of a person's head. The month of Adar represents the "nose". Sweet smell, says the gemara Brachos [44b], gives pleasure not to the body but rather to the Neshama. The Bnei Yisaschar explains that when Adam and Chava ate from the Eitz HaDaas [Tree of Knowledge] they used all their senses for the aveira [sin] except their sense of smell. The pasuk says: she saw, she listened, she touched, and she tasted. But nowhere does it say that anyone smelled. Therefore the sense of smell has a certain purity that is unmatched by the other senses.
It is therefore appropriate that for the great Nes [miracle] that took place in the month of Adar, the month of smell, that both of the heroes of Purim, Mordechai and Esther had names referring to smell. Mordechai's name says the gemara Chulin [139b] is hinted in the name of the fragrance used in the Ketores called Mor Dror or Mira-Dachya as translated by Unkelos. Esther's real name, the Megila tells us [2:7], was Hadassa - the sweet smelling myrtle tree. Since a person's name represents their true inner self, Mordechai and Esther with their lofty purity were able to avoid the pitfalls of Achashveirosh and his materialism during his party and even while living in his palace. During the special month of Adar where these qualities reign supreme, these two pure tzaddikim saved Klal Yisroel from destruction.
