Mitpachat Sefarim, Part I, on the authorship of the Zohar, Tikunei HaZohar and Midrash HaNe'elam, and Part II, critique of R. Aviad Sar Shalom Basilea's Emunat Chachamim, by R. Yaakov Emden. Altona: printed in the author's home, [1768]. First edition.
This book was printed by the Yaavetz in a limited number of copies and for many years was scarce (the second edition was printed in 1870).
Mitpachat Sefarim is a critique of the Zohar and an attempt to authenticate its authorship and date of composition. As is well known, the Yaavetz declared war on the Sabbateans and their sects. The impetus behind this publication (as explained by the Yaavetz in his preface) was the inappropriate use of the Zohar and Kabbalah by the Sabbateans. In this work, the Yaavetz attempts to discredit the Zohar by claiming that it was not written entirely by Rabbi Shimon bar Yochai as is commonly accepted, that parts of it were written at a later date, and that "it includes dubious material of uncertain and false authorship…". The Chida (Shem HaGedolim, Maarechet Sefarim, entry Zohar) is critical of this analysis of the Yaavetz, but attempts to advocate that "it seems to me that even the great rabbi [the Yaavetz] recognized the truth of the Zohar. However, in his zeal to eradicate the cursed Sabbateans who base their inappropriate acts on the words of the Zohar, he attempted to uproot the basis of their actions, and his intent was for the sake of Heaven…".
Signature on title page (deleted with ink).

50 leaves. 20 cm. Browned paper. Good-fair condition. Stains. Worming affecting text, repaired with paper. Minor open tear to leaf 7, affecting text, repaired with paper (with photocopy replacement of missing text). Print indistinct in several places (due to poor quality of printing; several lines of text were later touched up with ink). Stamps of the Strashun library in Vilna and other stamps. New leather binding.