A major question begs to be asked about Purim. A very difficult gloss of Rabbi Moshe Isserles (16th-century Ashkenazi decisor) in his Laws of Purim states: "Concerning the custom of wearing costumes on Purim ("false faces," partzufim) and for men to dress in women's clothing, there is no prohibition of this conduct. The intent is merely for the sake of rejoicing." Now why should Purim rejoicing outweigh the biblical prohibition against cross-dressing? Is masquerading so central to the festivities? In order to understand our sages, I believe it is necessary to go back to the first biblical personality who masqueraded: Jacob, who dressed as his elder brother Esau (Genesis 27:15, 16) in order to receive their father's blessing. What would cause Jacob, a "wholehearted individual, a studious tent dweller" (25:27) to don the aggressive outdoor garb of Esau? The truth is that Jacob wanted to become Esau because his own naive, introspective personality had been rejected by their father in favor of the more extroverted, silver-tongued ("His entrapment was in his mouth," 25:28) and materialistic Esau. So Jacob assumed a masquerade - and, as happens so very often when someone masquerades, that individual becomes the other, forsaking his true self; Jacob forsook the self which was the truest expression of the Divine spark within him, and exchanged it for the outer garb of Esau. And so the Jacob we watch in action for more than two decades with his uncle Laban becomes an accomplished businessman - a successful cattleman who had mastered the art of looking out for "No. 1." Perhaps this is why our English word "personality," or "persona," comes from the Latin word meaning mask; many of us feel we have to wear a mask all the time, and by so doing we forsake our truest selves. In this sense, Judaism would teach that external clothes don't necessarily make the man, but often fake the man. That's why the Hebrew begged, or garment, comes from a root which means to deceive, and the Hebrew me'il, which means outer cloak, comes from a root which means to embezzle. From this perspective, we can better understand the characters of the Esther chronicle. Jews in exile, especially Jews who wish to be accepted by the gentile host country, often masquerade to appear as gentile as possible. Hence the Jewish girl whose real name was Hadassah (a myrtle branch, which blooms even in the desert) adopts the gentile sobriquet - or external calling card, as is were - Esther, from the Persian goddess Astarte; Mordecai assumes the Persian name Marduk. Esther spends 12 months in preparation for her night with Ahasuerus, being perfumed and cosmeticized so that her wholesome body will be "masked" by all sorts of external fragrances. When she ascends to her lofty position, she certainly doesn't dress as a Jewess, or reveal her true identity in any way. In like manner, "Mordecai told the courtiers that he was Jewish" (Esther 3:4) only to explain his refusal to bow to Haman. Obviously, he could not have been dressing as a Jew. Esther and Mordecai were both masquerading as Persians in order to attain and maintain positions of influence within the Persian court. Remember, however, that the Hebrew word for face (which is related to the word facade) is panim, which literally means the internal (self), the true being. Similarly, although exile by its very nature encourages masquerade, the Hebrew word galut actually means to uncover, and - as the Bible guarantees - there will always come a moment of truth, after which the assimilated Jew will return to his true self and re-establish his roots in his homeland (Gen. 15:16, Exodus 1:7, 8; Leviticus 26:44, 45). This will either happen in a profound moment of repentance, as when Jacob succeeded in exorcising the spirit and envy of Esau from within himself and returned "whole" to his ancestral home (Gen. 32:29), or when an anti-Semite such as Haman forces a moment of truth on Mordecai and Esther, and they decide to risk their lives for their people and their God. Purim asks us to recognize the falseness of our daily costume, and uncover our truest selves - the essence of the Divine which is at the core of every human being. But before we can even begin to search for our real beings, we must recognize that we are usually hiding ourselves behind false garb. This is the significance of the scene when Mordecai (led by Haman) is dressed in King Ahasuerus's garb, the clothes Mordecai thought he wanted to wear as an important leader. And this is why a male can even dress like a female at Purim. But ultimately Purim is the festival of truth - and the most painless way for the truth to emerge is not by the threats of a wicked Haman, but rather through the wine which brings out all secrets and reveals the true personality of us all. Hence we drink on Purim to discover who we really are. The writer is the founder and chancellor of Ohr Torah Stone Colleges and Graduate Programs, and chief rabbi of Efrat.