Introduction. The article discusses the motive of a “miracle in a fiery furnace”, based on the story of the Three Holy Children in the Book of Daniel. Methods. The study provides a comparative analysis of the Biblical topos about the trial by fire in Byzantine, Western European and Eastern sources. A semiotic approach of textual study is used. Analysis. In Byzantine hagiography and hymnography, the plot of the “Three Holy Children” was interpreted as a prototype of the Incarnation, so, the sacred situation was reproduced in new historical conditions. In the Lives of Bishops of Cherson, the plot about miracle in the furnace is used for construction the local sacred history. Similar motives are found in the narratives about the baptism of Rus, such as Vita Basilii (the fifth book of Theophanes Continuatus), Vita beati Romualdi by Petrus Damiani, Historia de predicatione episcopi Brunonis. In narrative about conversion of Özbeg Khan to Islam, literary plot was connected with shamanistic representations about the holy fire. Results. The Biblical topos of the “fiery furnace” underwent a semantic transformation within the framework of various discourses. It was used in Byzantine texts for constructing the Christian Identity, while was enhanced by Turkic mythology in Muslim tradition.