The so-called ‘Revelationes Sanctae Brigittae’ (RSB) represent a very influential Latin text within medieval European Christian culture, mainly consisting of a literary adaptation of revelations reputedly received by Bridget of Sweden, an important figure of the 14th century. As a matter of fact, the relevance of the visions, which encompass theological and political questions of the time, is attested by a prompt and vivid reception, yielding different Germanic and Romance translations, as well as an Old Czech tradition: Tomáš ze Štítného, a theologian and philosopher of South Bohemian origins, elaborated two Old Czech versions. The first one (delší verze) renders more accurately a Latin model text, while the second one (kratší verze) clearly reworks the aforementioned Old Czech translation. Furthermore, each version addresses different readers, displaying hereby an obvious diaphasic variability. Analyzing the formal distribution of the relative pronouns in the two versions, this case study serves to affirm intertextual (and intratextual) variability and a shared renovation of the paradigm compared to inherited patterns. Finally, a first hypothesis is drafted, which for now attributes an important role to the complex linguistic reality of the time, where a prestigious Latin model language, multilayered contacts with German dialects and coexisting Old Czech varieties might have led to the formation of this fruitful historical evidence.