Taken from a twelfth-century Psalms commentary, compiled for Laurette d'Alsace (d. c. 1175) and written in vernacular French, the reference to the Jews as donkeys (nos asnes) appears in the commentary's exegetical interpretation of Psalm 40:14's ‘Blessed be the Lord God of Israel’. In this explanation, the Jews are defined as the pack animals bearing the weight of Scripture, i.e. the Hebrew Bible, the prophetic contents of which justify Christianity's veracity and supersession of Judaism. This interpretation of the Jews, albeit with some key differences, has its roots in the use by St Augustine (d. 430) of this particular verse and that of Psalm 58:12, with its injunction to ‘slay them not’, to develop his concept of Jewish service to Christianity, his testimonium veritatis, Jewish witness to the truth of the Christian faith. This paper discusses St Augustine's construction of that concept, together with its impact on subsequent Christian–Jewish relations, and the various ways in which the concept was disseminated into twelfth-century Christian society, in particular via the vernacular tongue, and thus into literate lay society.

The discussion focuses on three particular vernacular sources: first a selection of Psalms taken from Laurette's Psalms commentary, including Psalm 40; second, the twelfth-century French vernacular religious poem Eructavit, based on Psalm 44 and dedicated to Marie de Champagne (d. 1198); and lastly the twelfth-century vernacular versions of the Latin sermons on the Song of Songs originally composed by Bernard of Clairvaux (d. 1153), a translation that is believed to have been for the purposes of a lay audience. St Augustine's theory of Jewish service was no longer the purview only of learned Latin clerics; by the twelfth century it was also being disseminated to a literate lay society, both men and women.

Much has been written on the growing use, in the twelfth century, of vernacular French and the importance of women in its development. Ian Short has extensively discussed the growth and spread of Anglo-Norman as a language and its related literature, while Susan Groag-Bell and Jocelyn Wogan-Browne have both written ground-breaking studies regarding medieval women's book ownership and their roles as patrons of vernacular writings.