Bass's chief work is his bibliographical manual "Siftei Yeshenim" (Lips of the Sleepers; compare Shir haShirim Rabbah to 7:10). This work contains a list of 2,200 Hebrew books, in the alphabetical order of the titles, conscientiously giving the author, place of printing, year, and size of each book, as well as a short summary of its contents. The majority of the books described he knew at first hand; the description of the others he borrowed from the works of Buxtorf and Giulio Bartolocci (from the latter only in the first part).