The article examines the issue of the volume of the literary heritage of Archbishop of Novgorod and Pskov Simeon. In modern reference books, two works are attributed to him: the Homily to the Pskovites, which has come down to us as part of a number of chronicles, and the Epistle to the Snetogorsky Monastery, preserved in the miscellany of the State Historical Museum, Synodal collection, No. 562. The article proves that Archbishop Simeon owned the third text — Homily on Prayer being in the miscellany of the 1550–1560s. State Historical Museum, Synodal collection, No. 935. For this, the author of the article sees the following reasons: 1) the text of the Homily is inscribed with the name of “Archbishop of Nougorod Semyon”; 2) the text came to us in a miscellany of Pskov origin; 3) the text contains borrowings from the Sermon on False Teachers, taken, most likely, from the Trifonovsky Miscellany (Russian National Library, Sophia collection, No. 1262, late 14^th — early 15^th centuries), of a Pskov origin, donated in the Novgorod Vidogoshchsky Monastery, that is, easily accessible to the Novgorod-Pskov author. Considering the fact that in the title of the text Simeon is called the Archbishop of Novgorod, the Homily on Prayer dates back to 1416–1421. The article is accompanied by the publication of the Homily on Prayer.