Just in time for Parshat Mishpatim, Hebrewbooks.org uploaded Abravanel's Ateret Zekeinim. This book is discussed at length in Eric Lawee's Harvard dissertation (also published in book form) - "Inheritance of the Fathers": Aspects of Isaac Abarbanel's stance towards tradition and the subject of his article - Isaac Abarbanel's "Stance toward Tradition": The Case of "'Aṭeret zeqenim" (AJS Reveiw '97). As Lawee describes it:
Written in Lisbon sometime in the middle or late 1460s or early 1470s, the tract is, in its outer structure, a study of a single biblical passage (Exodus 23:20-24:18), but it treats a host of broader themes: providence, prophecy, the uniqueness of the Jewish people and their Land, ultimate human felicity, and the like.17
In later life, Abarbanel would look back on 'Ateret zeqenim as a "small composition" written in his early manhood.18 Yet if short and circumscribed by the standards of later works, Abarbanel's first work is well worth studying inasmuch as it introduces well both its author and his vast literary corpus, broaching many of the subjects that Abarbanel would treat thematically in later writings and exemplifying the literary character which his subsequent biblical commentaries (of which it should be considered the first) would take.
In addition, 'Ateret zeqenim calls attention to the theme of Abarbanel's relationship to the Jewish past in diverse ways, among them by making a case for exegetical independence and intellectual innovation in its introduction; by presaging principles that Abarbanel used to delimit midrashic authority in later works, and by revealing points of contact and conflict that animated Abarbanel's relationship with his most revered medieval predecessor, Maimonides, and with Maimonides' late medieval "esoteric" interpreters. (Still another prefigurative feature of the tract not touched on in the following is the stance of formal but qualified allegiance to Kabbalah adopted by Abarbanel therein as it resurfaces in later writings.)19
In short, 'Ateret zeqenim provides a unique and revelatory glimpse of Abarbanel at the earliest stage of his literary career standing before time-honored rabbinic traditions and the main medieval claimants to the mantle of Jewish tradition, the philosophers and kabbalists.
Finally, 'Ateret zeqenim points to larger questions summoned by the wide-ranging and elusive term "tradition"20( e.g., when do traditions re-main stable? why do they change? what patterns of change are evinced?)2' and, more specifically, highlights characteristic quandaries faced by writers working within a religious tradition: when and in what areas is critical thinking concerning traditional texts sanctioned? who are the authoritative interpreters of tradition? what is the basis of their authority? at what point does reinterpretation of tradition subvert it? what theological justifications exist for modem-day efforts to discover and advance new insights?22
[Update: ואברבנאל הואיל ואתא לידן - See here for a letter and testament of Abravanel. A critical edition of Abravanel's letters can be found here.]