Brought to England in the thirteenth century at the instigation of English statesman, scholastic philosopher, theologian, scientist and Bishop of Lincoln Robert Grosseteste, Cambridge MS Ff.1.24 was probably written in Constantinople in the tenth century.
"Twelfth and thirteenth-century scholars were aware that many important theological, philosophical and scientific texts unavailable in the West circulated in the Greek-speaking world. Only a tiny number went to the lengths that Grosseteste did to learn Greek with the aim of obtaining, reading and translating these works.
"The chronicler, Matthew Paris, tells how in the late 1230s, one of Grosseteste’s assistants, John of Basingstoke, recalled seeing a Greek manuscript containing a text called the Testaments of the Twelve Patriarchs in the library of the metropolitan Michael Choniates when he was in Athens some 40 years earlier. The bishop sent envoys to Athens and MS Ff.1.24, almost certainly Choniates’ copy, was brought to England for him. There are notes in Grosseteste’s hand throughout, demonstrating that he read the whole codex.
"He used the manuscript to prepare a Latin translation of the Testaments which was completed in 1242. Some early manuscripts of the translation contain a colophon recording how Grosseteste produced his text with the help of magister Nicholas Grecus, a native speaker and member of his household.
"Grosseteste and his contemporaries believed that the Greek text was a translation of a Hebrew original consisting of the genuine deathbed exhortations of the twelve sons of Jacob. They identified within the text various passages prophesying the coming of Christ. In translating the text, Grosseteste intended it to be used to convince Jews to convert to Christianity.
"Modern scholarship on the Testaments suggests that it was composed in the first or second centuries C.E. Opinion is divided as to whether it is a Christian work that draws on Jewish sources or a Jewish work with Christian prophetic passages inserted.
"Grosseteste’s translation was enormously popular; over eighty manuscripts survive and there were numerous printed editions. It was the source for vernacular translations into English, French, German, Anglo-Norman, Danish and Czech.
"MS Ff.1.24 offers an insight into the working habits and library of a major intellectual figure of the thirteenth century and, more broadly, casts light on the tradition of Greek scholarship and transmission of Greek texts in the Medieval West" (http://cudl.lib.cam.ac.uk/view/MS-FF-00001-00024/7, accessed 02-28-2013; the links are my additions).
A digital facsimile is available from University of Cambridge Digital Library at this link.