Good and evil are mixed in the womb of Rivka, however it is incumbent on the side of good to neutralize, overcome and remove the evil [even the natural, positive side of it], which is why the angel silences Nevuchanezzer who wants to praise Hashem [Sanhedrin 92b]. That explains the words of Rivka to Yaakov "וְקַֽח־לִ֣י מִשָּׁ֗ם שְׁנֵ֛י גְּדָיֵ֥י עִזִּ֖ים טֹבִ֑ים" - and bring me two choice kid goats, on which the Medrash explains "טובים לבניך שעל ידן מתכפר להן ביום הכיפורים" - "Choice for your children through which they will attain atonement on Yom Kippur." Two goats, where the goat to Azazel - thrown over the cliff in the desert - corresponds to the evil side and the praise that emerges from the Evil. Therefore, the לשון זהורית - scarlet wool, would be divided, part on the goat and the other part on the opening of the Heichal. When the goat would reach the desert, the scarlet would whiten, indicating that their sins had been forgiven. The praise only came from the righteous צדיקים and the good would completely supplant and displace the evil. The Teshuva of Yom Kippur causes evil to dissipate.
The intention of Rivka was that Yaakov should merit the Brachos both as taste and smell. "ואעשה אותם מטעמים כאשר אהב" - "I will make him delectables [taste and smell] as he loves". When Yaakov brings the food, Yitzchak says to him, ,"הַקֹּל֙ ק֣וֹל יַעֲקֹ֔ב וְהַיָּדַ֖יִם יְדֵ֥י עֵשָֽׂו" - "The voice is the voice of Yaakov and the hands are the hands of Esav." Yitzchak discerned that the two aspects joined together, the voice of Yaakov, representing Torah, and the hands, representing the forces of nature. When Yitzchak wanted to see if he has the element of ריח - the Kedusha of the Avos, it says " וַיָּ֛רַח אֶת־רֵ֥יחַ בְּגָדָ֖יו וַֽיְבָרְכֵ֑הוּ וַיֹּ֗אמֶר רְאֵה֙ רֵ֣יחַ בְּנִ֔י כְּרֵ֣יחַ שָׂדֶ֔ה אֲשֶׁ֥ר בֵּרְכ֖וֹ יְהֹוָֽה " - He smelled the scent of his garments and blessed him, "See, the scent of my son is like the scent of the field which Hashem has blessed." This means that Yaakov has those powers of nature with which the Avos were blessed. That is what Yaakov meant when he said that he is the Bechor. I am called "בני בכורי ישראל". Through the mandate of the Holy Torah, the Avoda was transferred to the Leviim. There is exchange and redemption for the first born [like Esav] but not for the Leviim. Even if Esav was physically born first physically, in the world of Divine "thought" - עולם המחשבה, Yaakov is first.
The victory of good over evil, the value of Kedushas Ha-Levi over the natural Kedusha of the Bechor, is enhanced by Eretz Yisrael. The return to EY is a return to Kedusha and the natural habitat of the Jewish people. Also, only in Eretz Yisrael can the Kedusha of ריח be exposed. In Chutz La-aretz the טומאת ארץ העמים - impurity of the foreign lands, intervenes and blocks the fragrant aroma. Yitzchak was not allowed to leave EY and was not allowed to take a non-Jewish maidservant [as did Avraham] even though he was barren, b/c he was completely בחינת ריח - reflected smell and natural Kedusha at its best. He was the first person in history BORN a natural Jew. Since he was natural Kedusha, he deemed Esav worthy of the bracha. Avraham who went to Chutz La-aretz and took Hagar as a wife, understood that his natural Bechor Yishmael was not on the same level as Yitzchak. Less ריח. Yaakov also went to Chu"l and even married two sisters b/c in Chu"l he didn't "smell" the sin of marrying two sisters. The mitzvos in Chu"l are "far away news" that come from EY. "ושמועה טובה מארץ מרחק" - A good tiding from a distant land [Mishlei 25-25]. Yaakov didn't receive this distant communication about not marrying two sisters. Yaakov felt the element of ריח when he came into EY and thus Rochel died so that he wouldn't be married to two sisters in EY, as the Ramban writes "עיקר הכתוב בארץ" - The Torah was given primarily for EY.
This is alluded to in the pasuk [Vayikra 26-42]
"וְזָכַרְתִּ֖י אֶת־בְּרִיתִ֣י יַעֲק֑וֹב וְאַף֩ אֶת־בְּרִיתִ֨י יִצְחָ֜ק וְאַ֨ף אֶת־בְּרִיתִ֧י אַבְרָהָ֛ם אֶזְכֹּ֖ר וְהָאָ֥רֶץ אֶזְכֹּֽר"
"And then I will remember my covenant with Yaacov; and also my covenant with Yitzchak, and also my covenant with Avraham; and I will remember the land".
EY causes the sanctity of smell. Smells are handled by the olfactory bulb, the structure in the front of the brain that sends information to the other areas of the body’s central command for further processing. Odors take a direct route to the limbic system, including the amygdala and the hippocampus, the regions related to emotion and memory. Smell relates to memory. That is why the aromatic לבונה is called אזכרתה [see Vayikra 2-2]. Thus, it is in EY the place of ריח that the memory of the Avos who "specialized" in קדושת הריח is aroused. When Yitzchak smelled Yaakov and reveled that he possesses קדושת הריח, he then blessed him.
[עפ"י דרשת מרן הרב זצ"ל סעודה שלישית תר"ץ]
