Three years ago, Patrick Andrist published a study listing an impressive register of manuscripts containing Christian literature against the Jews. One item in particular caught my eye, because it targets a wider range of opponents: it is an anonymous sermon against the Hagarenes, the Bogomils, and the Jews, and, more specifically, their hatred of the cross. This work, meant to be read on the third Sunday of Lent, has been preserved in one manuscript only: Athos, 388 (16th c.; 8°; 994 folios), a voluminous paper codex with various contents. The text, which runs from fol. 426r (431r), line 19, to 427v (432v), line 40, was written by a quick but rather inaccurate hand, as is shown by the numerous abbreviations, the presence of two lacunae, and the lack of quite a few initial capitals, which should have been added by the rubricator. The sermon is of unknown date, but the In exaltationem uenerandae crucis et contra Bogomilos of Germanos II, patriarch of Constantinople-Nicaea from 1223–1240, gives us a clue, as a major portion of lines 9–83 of our sermon can be found in this work (PG 140.621–44). In this article I present the editio princeps of the Greek text, accompanied by both an apparatus fontium and an apparatus criticus.