The root Adar appears five times in the Torah. The rule is that the first appearance of a root in the Torah is the most important and expressive of all. The first appearance of the root “Adar” in the Torah is in Genesis 25:25, refers to the birth of Esau: “And the first one emerged ruddy, completely like a cape of hair (Aderet [root of Adar] se’ar), and they called his name Esau.” This is the root of Adar in the Torah, aderet se’ar. The Torah refers to only two people as red-complexioned: Esau and King David. From this we learn that King David, the King Mashiach, comes to rectify the red-complexioned Esau.
In Hebrew, the word for “red” is adom, cognate to Adam. There is something red in the essence of man. Adam is also cognate to adamah (earth). Apparently, the archetypical earth is red clay. The word admoni (אדמוני) used to describe the red-complexioned Esau has the numerical value of 111, which is the same numerical value as the word פלא (wonder( and אפל (dark). In the personality of man, we have an illuminated side and a dark side. (This is the secret of “according to the will of איש ואיש(this man and that man)” in the Scroll of Esther. In the redemption, the verse “איש ואיש (this man and that man) will be born in it” will be fulfilled. The average value of איש ואיש is Mordechai Hayehudi (the hero – along with Queen Esther) of the Scroll of Esther. His illuminated side is white, while the dark side is red. There is something red in the dark side.
Every person has their Jacob and their Esau, who are also their Mordechai and Haman. The illuminated side is Jacob and Mordechai. The dark side is full of potential. Who sensed Esau’s potential? His father, Isaac. Hence “And Isaac loved Esau, for “there was hunting in his mouth.” Esau hunted him with his words. In the Torah portion of Mishpatim it says, “And he did not hunt, and God brought it to his hand and I will appoint for you a place to where he can flee.” Rashi on this verse provides us with a lengthy analysis of the root of the word צדה (hunt) and concludes that the meaning is like an ambush. Apparently, each of the sides of a person’s personality – the illuminated side and the dark side – lie in ambush for each other.
Esau is full of potential. It is impossible to bring the redemption without him. The Lubavitcher Rebbe said that in our generation, Esau is ready – the dark side is ready for “the advantage of light over darkness.” In potential, he has more light than the original light.
Why is the month of Adar connected to the dark side? First, Haman was happy that the lot fell on the month of Adar. The sages say that he was happy because he knew that Moses had died in the month of Adar. In general, though, there is something about Adar that is a dark month, the month of Esau, who was born like an aderet (Adar) cape of hair.
The holiday of the month of Adar is Purim, the month in which everything is transformed. On Purim we eat and drink until we don’t know the difference between “cursed is Haman” (the dark side) and “blessed is Mordechai” (the illuminated side). On Purim, we have to reach a state in which we cannot differentiate between the dark side and the illuminated side, a state in which all seems the same; one simple unified state.
The first appearance of Adar in the Torah in connection with a garment (cape) shows the connection of this month to garments and the world of garments. It is customary to wear a costume on Purim. This Purim, we can wear the cape of Esau and transform it into the cape of Elijah the Prophet.
Esau means “completed” and indeed, Esau was born completed. The time has come for us to complete the clarification of Esau. The Lubavitcher Rebbe said that we have already completed the service of clarification. Everything is finished, everything is Esau (completed).
 Psalms 87:5.
 Genesis 25:28.
 Exodus 21:13.