The pasuk that introduces Parshat Toldot, the Torah section most devoted to and focused upon the personality of Yitzchak Avinu, commands our attention: "Eileh Toldot Yitzchak ben Avraham; Avraham holid et Yitzchak". The mefarshim were understandably intrigued by this dual, seemingly superfluous depiction of Yitzchak Avinu's bond with his father. The Orach Chayim, for example, offers no fewer than nine insights signified by this apparently self-evident proclamation.
Numerous mefarshim perceive this pithy formulation as a crucial statement about the character and legacy of the fledgling Klal Yisrael. Let us briefly examine some of these perspectives.
Rashbam accentuates the sharp contrast to the Torah's earlier description of Yishmael (25:12):"ve-eileh Toldot Yishmael ben Avraham asher yaldah Hagar ha-mizrit shifchat Sarah le-Avraham". Invoking the previous passuk (21:12), "ki be-Yitzchak yikarei lecha zara", he asserts that "Avraham holid et Yitzchak" reinforces the doctrine that "ikar ben hayah le-Avraham", that Yitzchak Avinu alone inherits Avraham's spiritual mission and leadership mantle. [This view is further reinforced and supported by Divrei ha-Yamim 1:1:28, 34. Ramban and others also subscribes to this view. Kli Yakar underscores the difference between a ben and a velad. While the former may connote more superficial or intellectual influence, the latter implies a common nature and character.]
Rav Saadia Gaon and Ibn Ezra expand upon the contrast between Yitzchak and Yishmael. They suggest that this introductory declaration, "Avraham holid et Yitzchak" attests to the significant educational, emotional and spiritual effort that Avraham invested in Yitzchak ("gadal veravah"), particularly in aftermath of Sarah's directive that he distance himself and Yitzchak from Yishmael. Only an intense and sustained mentorship could secure the future of people destined to become a "mamlechet kohanim ve-goy kadosh".
Radak suggests that "Avraham holid et Yitzchak" also refers to how others instinctively responded to Yitzchak. His posture of empathy and kindness engendered the reflexive reaction that they were encountering the son of the amud ha-chesed. This capacity was unquestionably a result of Avraham's mentoring program, and also a pivotal reason that "ki be-Yitzchak yikarei lecha zara", why the legacy was fully entrusted to this particular "ben Avraham". Radak's insight is particularly fascinating given the fact that Yitzchak's own legacy to Klal Yisrael concentrated upon the very different character specialty of gevurah. It highlights the important principle that not only are these different emphases not mutually exclusive, but they must, in fact, coexist, overlap, and that gevurah, in particular, must be predicated upon the foundation of Avraham's chesed. While we emphasize "Elokei Yitzchak" alongside "Elokei Avraham" in our tefillot, we conclude (chotemin) by returning to the persona of Avraham-"magen Avraham".
Moreover, Radak's view coheres with an important phenomenon in Yitzchak's (and, by extension, Klal Yisrael's) life that we have developed previously (Who is Yitzchak and What is His Legacy). Notwithstanding Yitzchak's very different persona (gevurah) and circumstances- as the child of the Akeidah, the olah temimah, the first native Jew etc.- the most powerful force in his life is his self-image and sense of destiny as his father's son. "Avraham holid et Yitzchak" is not merely a testament to the transmission of Avraham's special middot, but to his worldview and enduring impact that inhered in Yitzchak, even after Avraham's petirah, as well. [See the comment of Neziv in Haamek Davar, "zehu bichlal Toldotav - she-bekol derachav ve-halichotav hayah nikar ve-rashum she-hu beno shel Avraham". He contrasts this salient, defining element with Yishmael, Avraham's other biological son.] This perspective is not confined to the avot and their interrelationship, but has always defined the self-image and aspirations of the total Klal Yisrael. It is a crucial dimension of the principle of "maaseh avot siman le-banim."
Finally, "Avraham holid et Yitzchak" transcends specific middot, even the enduring impact of the avot. It unequivocally and compellingly established at the very beginning of Klal Yisrael's history, with the first father-son link in what would become a magnificent chain of singular Torah personalities, that the concept of mesorah - personal transmission and absolute self-identification from generation to generation - was to serve as an indispensable linchpin in securing the spiritual destiny of Am Yisrael. Despite and because of the independent contributions of each of the avot, and, by extension, each of the great Torah personalities that has immeasurably enriched our Torah Tradition, "Avraham holid et Yitzchak" defined a community of chachmei mesorah and the aspirations of Torah Society. [This ubiquitous theme is also captured in the Torah's shirah: "zeh Keili ve-anvehu, Elokei avi va-aromemenhu", "Sheal Avichah ve-Yagedcha, zekeinecha ve-yomru lach".] Kach hi darkah shel Torah, u-mesorah. From the very earliest origins, Klal Yisrael has constituted a Mesorah community, crystallized powerfully if succinctly with the words that introduce the first native Jew: "Eileh Toldot Yitzchak ben Avraham; Avraham holid et Yitzchak".
[This theme constitutes the basis for the vaunted notion of chidush in Torah. An extensive and profound understanding of this concept enables us to decipher and appreciate statements like "kol mah she-talmid vatik atid le-chadesh neemar le-Moshe mi-Sinai" and others. I hope to elaborate these concepts elsewhere. The phrase and focus on "mesorah community" as a living and indispensable motif in halachic life was a major theme in the Rav's thought. See, for example, the concluding section of U-Bikashtem Misham (19), and Iggerot ha-Grid, Hilchos Kidush ha-Chodesh 5:1-2, p. 87.]