How can cultural knowledge, that is relevant to understanding legal texts, be built up for Finnish law students in teaching legal German as a specialised foreign language? An essential prerequisite in transcultural legal communication is to comprehend foreign-language legal texts in their respective cultural contexts. In this interdisciplinary work, a performative approach is developed on the basis of a constructivist concept of culture. At the centre of this is a knowledge- and performance-oriented interpretation model that aims to achieve a culturally appropriate understanding of foreign-language legal texts. With reference to the knowledge orientation in specialised communication research, a performative-discursive understanding of law is assumed. In addition, the cultural studies-based construction of subject-constituting knowledge frameworks in law is placed in a legal-theoretical paradigm. On the basis of the neurhetorical concept of the "universal auditorium", possible references are shown to capture subject-specific communicative action in the context of foreign language teaching. Due to similar procedural structures that underlie both the interpretation model and the universalisation processes of legal argumentation, this work brings together ways of thinking in law and cultural studies from a subject-specific communicative perspective to form an innovative approach.