1. Yitzchak enters the narrative with Rivkah
In Parshat Toldot, Yitzchak takes the stage in earnest. This is Yitzchak’s parasha. In the previous parshiyot Avraham was the key figure of the narrative. After Parshat Toldot, Yaakov will become the central character. In Parshat Toldot the Torah describes Yitzchak's trials and challenges. However, in both the opening and closing episodes of the parasha Yitzchak shares the stage with his wife Rivkah. In fact, it is Rivkah's role that is more central to the narrative.
In the opening episode of the parasha, Rivka is pregnant with twin sons. She experiences terrible pain and seeks the council of a prophet. The prophet reveals to Rivkah that she carries the progenitors of two great nations. The younger of her sons will dominate the elder. The pain that she experiences is a harbinger of the conflict that will exist between her sons.
In the parasha’s final episode Rivkah successfully plots to divert to Yaakov a blessing that Yitzchak intends for Esav. In short, Rivka is not presented as merely a supportive partner of her patriarch husband. She is described as an active and central figure in the drama. She seeks to understand the meaning of events and to shape destiny based upon this understanding.
Now these are the generations of Terach. Terach begot Avram, Nachor, and Haran; and Haran begot Lot. And Haran died in the presence of his father Terach in the land of his nativity, in Ur Casdim. And Avram and Nachor took wives. The name of Avram's wife was Sarai; and the name of Nachor's wife, Milcah, the daughter of Haran, the father of Milcah, and the father of Yiscah. (Sefer Beresheit 11:27-29)
2. Avraham and Sarah as partners
The characterization of Rivkah as Yitzchak's active partner mirrors the Torah's description of Sarah and Avraham. In its treatment of that relationship the Torah places greater emphasis on the role of Avraham. Nonetheless, the Torah describes Sarah as perceptive and bold. Like her successor Rivkah, she seeks to understand her circumstances and she acts to shape destiny. In its dealing with Avraham and Sarah and its description of Yitzchak and Rivkah, the patriarch and matriarch of each pair are treated as partners, together shaping the future of Bnai Yisrael.
The paradigm of the patriarch-matriarch partnership is evident from the very beginning of the Torah's introduction of Avraham. In those first passages the Torah introduces Avraham along with Sarah. In fact, the Torah reveals nothing of significance regarding Avraham's life and activities from the period preceding his marriage to Sarah.
Rav Yosef Dov Soloveitchik Zt”l notes that when Hashem reveals to Avraham that his name will be changed from Avram to Avraham, He, at same time, reveals that Sarah's name has been changed from Sarai. Together they received new names signifying that they are jointly the teachers of humanity.
Rav Soloveitchik also notes that with the passing away of Sarah, Avraham yields the center stage of the Torah's narrative to his son Yitzchak. The two last episodes in which Avraham plays a key role are the burial of Sarah and the assignment to Eliezer the mission of finding a wife for Yitzchak. The implication of these episodes is that with the passing of Sarah, Avraham must also be replaced and that the ascent of Yitzchak as patriarch is tied to the entrance of Rivkah as matriarch.
In a general sense, Rivkah and Sarah played similar roles. Both were active partners with their husbands. Both demonstrated insight and wisdom and used their understanding to shape events. However, if these two matriarchs are studied more carefully, it is evident that their particular roles were very different from one another. Each fulfilled a role that was specifically suited to forging a partnership which combined the strengths of each member.
And Sarah saw the son of Hagar the Egyptian, whom she had borne unto Avraham, making sport. She said unto Avraham: Cast out this bondwoman and her son; for the son of this bondwoman shall not be heir with my son, even with Yitzchak. And the thing was very grievous in Avraham's sight on account of his son. (Sefer Beresheit 21:9-11)
3. Hashem sides with Sarah’s ethical counsel
In the above passages Sarah demands that Avraham send away his son Yishmael. At first, Avraham resists Sarah's demands. However, Hashem directs him to obey Sarah's instructions and do as she counsels. What motivated Sarah and why did Avraham resist?
Sarah understood that her son Yitzchak would be the one to carry on Avraham's mission. She appreciated the importance of this mission and recognized that she and Avraham must assure that Yitzchak's role as successor be beyond dispute. She sensed that Yishmael's continued place within the family as Yitzchak's older brother could only lead to confusion and to a dispute over who should be the heir to Avraham's legacy. Sarah understood that she and Avraham must therefore send away Yishmael.
Avraham was not unaware of this consideration. However, he deeply believed that as Yishmael’s father he was obligated to educate, nurture, and develop him. He concluded that this moral obligation took precedence over Sarah's concern regarding the potential for confusion and dispute. He resisted her demands. However, Hashem revealed to Avraham that Sarah's perspective was the more correct and that he must yield to her demands. In short, Avraham and Sarah each championed different perspectives on a very challenging issue. Each could understand and appreciate the other's perspective, but nonetheless, each believed that he or she was correct.
What does this reveal regarding the nature of Avraham and Sarah's relationship? Sarah provided Avraham with an alternative perspective on important ethical issues. Both were wise but neither was always correct. Each benefited from exposure to his or her partner's view. Together they discovered truths that may have eluded each alone.
And Rivkah spoke to Yaakov her son, saying: Behold, I heard your father speak unto Esav your brother, saying, “Bring me venison, and make me savory food, that I may eat, and bless you before Hashem before my death.” Now therefore, my son, hearken to my voice according to that which I command you. Go now to the flock, and fetch me from there two good kids of the goats. I will make them savory food for your father, such as he loves. You shall bring it to your father, that he may eat, so that he may bless you before his death. (Sefer Beresheit 27:6-10)
4. Rivkah as a judge of character
Now, let us consider the relationship between Yitzchak and Rivkah. The Torah reveals that Yitzchak preferred his son Esav but Rivka preferred Yaakov. As Yitzchak ages and suspects that the end of his life is approaching, he summons his son Esav. He tells Esav that he wishes to confer upon him a blessing. Rivka overhears Yitzchak’s plans and devises a strategy to subvert Yitzchak’s intentions and divert the blessing intended for Esav to Yaakov. Yaakov collaborates with his mother and disguised as Esav, appears before Yitzchak to receive the blessing intended for his brother. The plan works and Yitzchak unknowingly bestows the blessing upon Yaakov.
This episode provides an important insight into Yitzchak. Yitzchak was prepared to bestow on Esav his blessing. He believed that Esav was more fitting for this blessing than Yaakov. Rivkah intervened. She understood that Yitzchak’s evaluation of Esav was inaccurate. Yaakov was the son most fit for this blessing. The blessing must be bestowed upon him.
This episode also reveals a fundamental difference between Rivkah and Yitzchak. Yitzchak was a trusting father and an optimistic judge of his son Esav. Rivkah was a perceptive and skilled judge of character. She better understood Esav and realized the extent of his limitations.
5. Two models of the patriarch-matriarch relationship
The relationships between these two patriarch-matriarch pairs can now be compared. In both pairs the members complemented one another. The manner in which they complemented one another differed in the pairs. In the Avraham-Sarah relationship, Sarah provided an important alternative perspective on ethical or moral imperatives. Avraham’s treatment of Yishmael was based upon prioritizing his role as father. He believed that his obligation to nurture and spiritually develop Yishmael was of higher priority than assuring that Yitzchak would be perceived as his undisputed heir. Sarah disagreed. She placed the highest priority upon the passing on of Avraham’s spiritual legacy to Yitzchak. She did not want any dispute to arise over Yitzchak’s role as Avraham’s sole spiritual heir. In other words, Sarah provided an alternative perspective on moral and ethical priorities.
Rivkah and Yitzchak shared a different relationship. Rivkah’s most impactful role was not to debate Yitzchak’s moral judgments and priorities. However, the implementation of any system of ethics requires that one understand and accurately judge people. Our understanding of others informs us whether we should befriend them or distance ourselves from them. This understanding dictates who we reward with our friendship and support. Yitzchak was trusting and optimistic in his assessment of others. Rivkah was shrewd and penetrating. She could not be fooled by superficial righteousness – the type demonstrated by Esav. She recognized Yaakov’s sincere commitment to spiritual values. She was an essential counter-balance to Yitzchak. She possessed an understanding of human frailty and failings that eluded Yitzchak.
And Rivkah said to Yitzchak: I am weary of my life because of the daughters of Chet. If Yaakov takes a wife of the daughters of Chet, such as these, of the daughters of the land, what good shall my life do me? (Sefer Beresheit 27:46)
6. Effective partnership in marriage
In short, Sarah provided Avraham with an alternative moral perspective. Rivkah provided Yitzchak with an alternative perception of character. However, in both relationships the effectiveness of the partnership was founded upon mutual respect and appreciation. Avraham and Yitzchak were patriarchs. They were the most advanced thinkers of their era. Both, in their individual ways, were great leaders. Nonetheless, each respected the perspective of their respective partners. This respect empowered the partnership. In the Torah’s narrative Sarah is completely at ease counseling Avraham to cast away Yishamael. She realizes that Avraham will resist. Yet, she speaks to him boldly and insistently. This is a discussion that can only take place in a relationship founded upon mutual respect and appreciation.
Rivkah does not openly confront Yitzchak. Apparently, she assumes that Yitzchak is not likely to share or understand her perspective on Esav. However, she is confident that her strategy to divert Yitzchak’s blessing from Esav to Yaakov will succeed and she is not concerned with Yitzchak’s response when he inevitably discovers her role. What was the source of this confidence?
Rivkah recognized that Yitzchak was the instrument of bestowing his blessing but that Hashem would only allow the blessing to be given to the appropriate son. Also, she understood that Yitzchak was aware of Hashem’s role in the assigning of the blessing. Therefore, she concluded that her plan was sure to succeed and that with its success, Yitzchak would accept that Rivkah’s assessment of their sons was correct. Rather than feeling antipathy toward Rivkah, he would value her initiative.
In fact, in the above passages, the Torah describes an interaction between these partners following Rivkah’s intervention in the assignment of the blessing. She urges Yitzchak to send Yaakov away to find a suitable wife. She speaks to Yitzchak with a tone of both familiarity and confidence. Her words reflect her certainty that far from resenting her intervention in the assignment of the blessing, Yitzchak appreciates her wisdom and insight into human behavior.
 Rabbaynu Shlomo ben Yitzchak (Rashi), Commentary on Sefer Beresheit 17:5, 17:15
 Rav Yosef Dov Soloveitchik, Recorded Lecture on Parshat Chayey Sarah
 Rabbaynu Yosef Bechor Shur, Commentary on Sefer Beresheit 21:10
 Rav Yaakov Tzvi Mecklenburg, HaKtav VeHakabalah, Commentary on Sefer Beresheit 21:11.