The discovery of Hebrew manuscripts of Ben Sira in the Cairo Genizah has shaped and transformed the interpretation of the book. It is argued here that a proper appreciation of the manuscripts themselves is also essential for understanding this ancient work. Since their discovery 120 years ago and subsequent identification of leaves, attention has been directed to the interpretation of the ancient book, the Wisdom of Ben Sira. Serious consideration should also be given to the Hebrew manuscripts themselves and their particular contributions to understanding the language and transmission of the book. The surprising appearance of a work that was preserved by Christians and denounced by some Rabbis raises questions over the preservation of the book. At the same time, diversity among the manuscripts means that exegesis has to be built on an appreciation of the individual manuscripts. The contributors examine the manuscripts in this light, examining their discovery, the codicology and reception of the manuscripts within rabbinic and medieval Judaism, and the light they throw on the Hebrew language and poetic techniques. The book is essential reading for those working on Ben Sira, the reception of the deuterocanon, and Medieval Hebrew manuscripts.