The marriage of Yitzchak to Rivkah is, actually, not the only instance in the Torah in which we are given a description of the development of a match between a man and woman. In parshas Veyeitzei, for example, we are told how Ya'akov met his wife Rachel, and in parshas Shemos we are told how Moshe met his wife Tzipporah.Why, then, did the Torah choose to teach us the providential nature of marriage in connection with the union of Yitzchak and Rivkah, rather than any other union it records? I believe that a closer look at the circumstances surrounding this union, and as well as the nature of that union itself, can help us answer this question.
As we have noted, Avraham sent Eliezer on his mission to find a wife for Yitzchak after Sarah had died.Thus, Sarah herself played no part in this process. Avraham was the guiding force, with Eliezer as his faithful servant carrying out his directives and desires. It is interesting to note that the eulogy Avraham gave for Sarah has been identified by the midrash as the final chapter of the book of Proverbs, or Mishlei, which speaks of the Eishes Chayil, the woman of valor. Assessing her after her death, he looked at her essence, and projected her as the ideal wife. When he sent Eliezer on his mission, this must also have been the kind of person he told him to find for Yitzchak.The woman of valor, in Mishlei, is described as having the teaching of chesed, or kindness on her tongue, and it was specifically the trait of chesed, that Eliezer was looking for in a wife for Yitzchak. When Rivkah exhibited that trait to the maximum in her treatment of Eliezer, he knew he had found the woman he was seeking. He proceeded to finalize the match, and brought Rivkah back to meet Yitzchak.
Yitzchak, on his end, also viewed Rivkah in an idealized way. The Torah tells us that he took her into the tent of Sarah his mother, she became his wife, and he loved her. Finally,says the Torah, Yitzchak was comforted after the death of his mother (Bereishis, 24,16). The midrash tells us that Rivkah renewed the practices of Sara, so that a special light was always lit in the tent from one Sabbath eve to the next, a divine cloud hovered over their tent, and a blessing was found in the dough she prepared. In short, Rivkah was a replacement for Sarah, just as, apparently, Avraham had intended.
What seems to be emerging in the relationship between Yitzchak and Rivkah is the personal element, that ties individuals together in a unique way, and helps open the channels of emotions and communication. The personal relationship that they had, evidently, developed after the marriage. Rabbi Naphtali Tzvi Yehudah Berlin, known as the Netziv, writes, in his Torah commentary Ha'amek Davar, that Yitzchak and Rivkah suffered from a lack of complete communication, as brought out in the events in the episode of the blessings related in next week's parsha. Rivkah saw that Esav was not worthy of these blessings, but she was not able to communicate this directly to Yitzchak. Rather, she asked Ya'akov to go through an elaborate subterfuge in order to receive those blessings. Why didn't she simply tell Yitzchak that his assessment of Esav was mistaken and that he was about to bless the wrong son? The Netziv explains that Rivkah could not communicate with Yitzchak on that level, because she viewed him as a holy man whom she held in awe. The first time she ever saw him his hands were stretched out in prayer. Overwhelmed by the holiness radiating from him, she fell off her camel. This initial view of Yitzchak set the tone for the rest of their relationship, and so, she found it difficult to tell him he was making a mistake and had to revert to a subterfuge to assure that it was Ya'akov who would receive the blessings.
The Netziv, in describing the relationship of Yitzchak and Rivkah in the way he did, did not, I believe, mean to criticize that relationship in any way. As he goes on to explain, there was a specific reason for Ya'akov to receive his blessings in the way he did, rather than in a direct way. In order for this to happen, the personal relationship they had needed to have the nature that it did. By extension, we can say that the idealized vision of Rivkah that Yitzchak had from the outset was also necessary for the events in their life together to occur in the way that they did. This relationship does not represent the kind of relationship that we find, for example, between Ya'akov and Rachel, where the Torah records that Yaakov loved Rachel even before their marriage. However, it was the kind of relationship that was necessary for Yitzchak and Rivkah in the roles that they played in the development of the Jewish people. It is, then, precisely for this reason that the Torah teaches us that marriages are made in heaven in connection with the union of Yitzchak and Rivkah. Although a superficial observer might think that their relationship was not ideal, the Torah is telling us that it was exactly the kind of relationship that they required in order to fulfill their unique missions in life and in Jewish history.
Interestingly the other specific example brought by the Talmud to show that marriages are made in heaven is the union of Samson with the Philistine woman Delilah, which is, again, a relationship that would appear to be less than ideal. Still though, it was a relationship that was ordained due to the needs of the Jewish people at the time. While the marriage of Yitzchak and Rivkah projects a different model of relationship from that of Ya'akov and Rachel, different couples have different needs. In all cases, however, the Talmud tells us, providence plays a role in the formation of the union.