This is an apocryphal Hebrew book of magic edited by Moses Gaster in 1896 from a 13th or 14th century manuscript from his own collection, formerly MS Gaster 78, now London, British Library MS Or. 10678. Gaster assumed that the text predates the 11th century, based on a letter by Rav Hai Gaon (939-1038) which mentions the book alongside the Sefer ha-Yashar, and that it may even date to as early as the first four centuries CE. Besides the medieval manuscript used by Gaster, a short fragment of the text survives in Cod. Oxford 1531. A new critical edition was printed in 1997 by the Israeli scholar Yuval Harari based on a variant text found in another manuscript.