Мусар к Берешит 5:12

The metaphysical significance of all this is that the world was created with the letter ב, in the word Bereshit, which is a veiled reference to ברכה, blessing, benediction. Since Adam had preferred to follow the advice of the serpent, the source of curse, he was cursed himself, and with him the whole universe. Our sages express this by saying that the serpent cohabited with Eve, and infected her with its pollutant. This is the reason why the next section in our Parshah deals with the סוטה, the wife suspected of infidelity, and why the husband's feelings are described as ועבר עליו רוח קנאה. I have already described the meaning of רוח. When the Torah speaks about רוח קנאה it refers to the spirit of impurity with which man has become infested from the time Adam observed the serpent having sexual intercourse with his wife (Shabbat 146a). The Kabbalists pointed out that the dichotomy that the serpent caused in this "lower" world, the potential discord between man and his wife, had parallel results in the Celestial Regions, where the matches are made (who is to marry whom down here on earth). Originally, Adam had been created male and female, or, in the words of Bereshit Rabbah 8,1, דו פרצופי, with two faces in opposite directions, their common back not being visible until after Eve had been separated from him. After that separation, man and his potential partner remain united as one in the Celestial Regions. When the serpent polluted Eve, all this changed. Rashi already comments that the use of the word איש, איש, twice in 5,12, indicates that the trespass committed is twofold, a) against one's partner in marriage on earth, b) against the "איש מלחמה" in the Celestial Regions, i.e. against G–d. This is so because she tore asunder what even in the heavens formerly belonged together. The "pollutant" that the serpent impregnated Eve with, is a spiritual concept, i.e. Eve's counterpart in the Heavenly Regions became polluted. Pardes Rimonim already warns against our thinking that the קליפה, impurity, actually penetrated the holy regions of the Heavens. What is meant is that the complaint, or accusation of the forces of impurity that were leveled against the human beings now became "audible" in those Celestial Regions. Since it is incumbent on the true judge to dispense true justice, G–d's primary inclination to dispense חסד, kindness, was thwarted and He was "forced" to vacate the throne of Mercy and move over to the throne of Justice, and thereby restrain some of the largess He had intended to bestow upon those who cleave to Him. This whole episode is known as the כניסת הקליפה בתוך הקדושה, the penetration of the "peel" into the domain of sanctity. I have dealt with this at length in my introduction Toldot Adam. This then is what is at the root of the words "the spirit of jealousy overcame him, since she had become defiled, etc." The Torah depicts the effect of what happened when Eve had been seduced by the serpent. When the Torah continues with the apparent alternative of והיא לא נטמאה, "she had not become defiled," the obvious reference is to the "Eve" of the Celestial Regions, the spiritual counterpart of womanhood which could not actually become defiled; actual impurity cannot enter those regions.