||Hemdat Yamim ("The Best of Days"), a major 18th-century Hebrew work of homiletics and ethics, comprising three volumes in the first four editions and four in the last two editions. Its impact on Jewish life and letters, first among the Ashkenazim, and later among the Orientals and Sephardim, has been very great. As it has come down, Hemdat Yamim is probably incomplete. The extant part deals with the halakhic observances and ethical behavior of a pious Jew who tries to attain the maximum religious elevation during the various holidays, fasts, and special days of the year. It is possible that a part of the work treating the ordinary days was lost because it was never printed. Each section of the work is a homily in which the author substantiates his ideas by interpreting biblical verses and talmudic and midrashic sayings in homiletical sequences. The writings offer examples of some of the best rhetoric in Jewish homiletics, and the beauty of the sermons helped to endear the work to all readers. Although the author frequently raises halakhic problems, he does not deal with them in a purely halakhic manner - his main objective being to instruct the reader in the hasidic or pious way of life. A product of ethical kabbalistic literature, Hemdat Yamim was especially influenced by the Lurianic Kabbalah, which flourished in both Eastern and Western Judaism from the beginning of the 17th century. Accordingly, each chapter of the work stresses the mystically symbolic significance of the 613 commandments and of every custom and tradition carried out within the framework of Jewish religious life. The deeds performed in this world are seen as a reflection of mystical processes in the divine world. Through his religious acts the pious, observant Jew participates in a mythical drama of war between the mystical powers of good and evil. In a Jewry which accepted the Lurianic Kabbalah almost without exception, Hemdat Yamim had literary and practical value - people enjoyed both reading it and following its teachings.
The work was first printed by R. Israel Jacob b. Yom Tov Algazi in Smyrna in 1731–32 (and subsequently five more times in the next generation). Although a major work and written only a few years before its publication, the author is unknown and the question of authorship remains one of the great mysteries in Jewish bibliography. That the work was written in the early 18th century and studied in depth by many of the best Jewish scholars and bibliographers heightens the irony of its anonymity. One fact seems clear, though some scholars have contested it in recent years, namely that the author was a Shabbatean. Scholars have detected many Shabbatean ideas and allusions hidden in the work; the most obvious, pointed out in the 18th century by R. Jacob Emden, the fanatic enemy of Shabbateanism, are the notarikons of Nathan of Gaza, the prophet of Shabbetai Zevi, included in some of the work's piyyutim. This fact gave rise to the belief, accepted especially in the East, that Nathan of Gaza was the author of the entire work. Accordingly, Nathan is sometimes known as Ha-Rav Hemdat Yamim because of the common practice of calling an author by the name of his major work. Although the book was written by a Shabbatean, it has been proved that Nathan of Gaza was not the author. First to disprove Nathan's authorship was Menahem Heilperin in Kevod Hakhamim (Jerusalem, 1896). Heilperin went even further, though unsuccessfully, in trying to demonstrate that the author had no connection with the Shabbatean movement. A recent effort to discover the author was made by Avraham Yaari in Ta'alumat Sefer, where he tried to prove that the author was Rabbi Benjamin ha-Levi, one of the major kabbalists in 17th-century Safed, who, according to Yaari, wrote the work during his old age in 1671–72. G. Scholem, in a thorough analysis, cited - among the many bibliographical and historical facts making Yaari's thesis unacceptable - the fact that Hemdat Yamim was written after R. Benjamin died. Further insight into the work was provided by I. Tishby, who proved conclusively that the author of Hemdat Yamim made extensive use of works published in the beginning of the 18th century. Thus, the book could not have been written before the second, or even the third decade of that century, a time approximating the date of its publication. The comparison between Hemdat Yamim and the sources on which it is based reveals that many chapters of the work are in fact anthologies gleaned from many books. But by changing numerous details and transforming the special character of the individual sources, the author integrated his diverse sources into a new whole. The author quoted ancient and medieval sources faithfully, but used the subject matter of contemporary sources in any way which suited the literary character of his work. Many "personal" experiences reported by the author were in fact taken from other works and adapted to the demands of his style and purpose.