The manuscript A 13 in the National Library of Sweden includes Jöns Budde’s (ca 1437–ca 1491) Old Swedish translation of Mechthild of Hackeborn’s (1241–1299) revelations. In early 17th century, the manuscript was owned by the Swedish antiquarian and librarian Johannes Bureus (1568–1652). Bureus is also the earliest scholar who after Budde’s lifetime has commented on a text translated by him. In this article, I focus on marginal notes that Bureus made in the manuscript A 13. The notes consist mainly of individual words that Bureus picked up from the text in the manuscript. The words were in most cases archaic and rare and therefore interesting in the eyes of Bureus. In some cases, he wrote Swedish synonyms or Latin equivalents in the margin. Bureus was not interested in orthography or morphology. Instead, he was interested in choice of words and of the meaning of the words. Some of the words are Low German loan words but it is unlikely that this was the reason why Bureus picked up exactly these words. In one case, Bureus drew an illustration in the margin depicting a cross. In some cases, Bureus seems to have found the contents of the text interesting. In one case, Bureus made an emendation because there was an obvious error in the text but it is though unlikely that Bureus collated the Old Swedish text with other versions of Mechthild’s revelations.