The article examines the sermon of the famous early 19th century Lithuanian preacher Jurgis Ambroziejus Pabrėža (1771–1849) to East Prussian Catholics, named “Sermon on great Happiness”, given on the occasion of the Great Jubilee on June 29, 1827 in Drangauskine (near Tilsit). This is the only known sermon of J. A. Pabrėža given in Prussia. The language and spelling of this sermon differ from other texts of the same period. The word Gylukys (in German: das Glück) used in the title of the sermon indicates that the author was prepared to adapt the text to the addressee. The article examines which Prussian Lithuanian publications J. A. Pabrėža used to prepare the sermon in a language understood by the addressee.