On opening Eustorg de Beaulieu’s Chrestienne Rejouyssance, one cannot help but notice the biblical references found in the margins of every page. This article proposes to analyse this annotation method, investigating the importance of these biblical references and the value they bring to the text. This study is based on a systematic analysis of the provenance and frequency of the various references. On this basis, one gains a better understanding of the biblical wells from which Beaulieu was drawing and of certain reading and writing practices of the period. However, the overwhelming number of biblical references also sheds light on the way they bolstered the legitimacy of the ‘spiritual songs’ as a genre by their biblical saturation, and of the author himself by putting his extensive knowledge of the holy text on display. Finally, these marginal notes invite reflection on reading practices they proposed, where spiritual song and biblical intertextuality come together.