SEFER HA-ḤAYYIM, an anonymous Ashkenazi-ḥasidic treatise, unique in its combination of mystical esoteric theology with ethical teaching. Whereas all other works of *Ḥasidei Ashkenaz deal with either one area or the other, the author of Sefer ha-Ḥayyim attempts first to establish a theological basis – beginning with the essence of God, His holy Names, and His different powers, and concludes with the ethical problems of good and evil tendencies among men, suggesting ways to overcome them. Because some theories in this work closely resemble basic kabbalistic ideas, Sefer ha-Ḥayyim is important for the history of Jewish mysticism. R. Moses *Taku attributes the book to R. Abraham *ibn Ezra. There seems to be no basis for this, however, even though the author used Ibn Ezra's exegetical and theological works. In the introduction of Seferha-Ḥayyim the author numbers 15 chapters, briefly describing their contents; the text, however, does not follow that structure, and entire subjects mentioned in the introduction are either missing or appear in a different order.
Y. Dan, Torat ha-Sod shel Ḥasidut Ashkenaz (1968), 143–56, 230–5; G. Scholem, Ursprung und Anfaenge der Kabbala (1962), 160f.