The article discusses two works of literature: Troilus and Criseyde, a long poem written in the genre of courtly romance (1382–1386/1387) by G. Chaucer, and ‘The Prophet’ [‘Prorok’] (1826), a poem by A. Pushkin. The two works are compared due to a common motif: the opening of the chest and swapping of the heart as a sign of the person’s spiritual regeneration. In her comparative analysis of the two poems, the author attempts to identify their common source or the likelihood of direct contact — whether Pushkin had come across Chaucer’s work and borrowed the motif directly. As for the heart being replaced, it seems both poets may have been inspired by several biblical stories. Further analysis of the motif of the chest being opened suggests that the research should focus on the Arabic tradition alone and take into account the potential influence of Islamic religious texts on Pushkin as well as Chaucer. Relying on the available data about Russian and European relations with the Arabic world, the article hypothesises about the ways in which the motif in question could have reached each of the poets. The author names the Quran as the common genetic source of the two poems.