German commentary on Ibn Ezra's mathematical work Sefer ha-Eḥad on the pecularities of the numbers 1-9. The numbered pages present Hebrew excerpts from Ibn Exra's work with a German commentary. The unnumbered pages seem to be either a corrected version of or notes on the commentary in the numbered pages. Reference is made to Ibn Ezra's commentary to the Pentateuch as well as his works Yesod Mora and Sefer ha-Shem. There is also an introduction describing the work and the commentary. Mention is made there of the first issue of the journal Jeschurun, published in 1856 in Lemberg, in which the work of Ibn Ezra appeared on p. 1-30, published from a manuscript with some brief notes.
