Among those who devoted themselves to Biblical study, St. Jerome stands out as the first scholar to emerge. In his Vulgate Latin Bible, he established a reliable text through textual criticism, presenting a version acceptable to intellectuals in the Roman Empire with its refinement into an elegant Latin translation. St. Jerome’s Epistle 106 is particularly significant in this context. The priests of Getae, Sunnia and Fretela, sent St. Jerome 177 questions about the so-called Gallican Psalter — the Latin psalms he translated from the Greek Septuagint around 386. Ep. 106 serves as a comprehensive response to these inquiries. This study aims to examine St. Jerome’s principles of textual criticism and translation through Ep. 106, exploring how he incorporated the classical tradition. St. Jerome’s textual criticism in Ep. 106 exhibits several distinctive characteristics. Firstly, he considered Origen’s revised Hexaplaric Septuagint to be the closest version to the original and followed this text. Secondly, he consulted not only the Greek text of the Septuagint but also the Hebrew text to identify variant readings. Thirdly, he selected a variant that best suited the context, relying on internal evidence and the assumption that the author wrote with consistent ideas. Fourthly, he rectified various scribal errors that occurred during transcription, noticing errors not only in Greek words but also in Hebrew words. Fifthly, he preserved the critical signs of the Hexaplaric Septuagint text, emphasizing their exact replication by scribes, thus inheriting this tradition from the Alexandrian textual criticism through Origen. Additionally, four principles of translation emerge in Ep. 106. St. Jerome consistently prioritized ensuring that the sense was not compromised. Secondly, he insisted on the translation being adorned with elegantia and proprietas. Thirdly, he respected the preceding translation, i.e., the translation of Vetus Latina. Lastly, he deemed the preservation of words important. Unlike Cicero, St. Jerome regarded a translation as superior if it managed to preserve words while also being elegant. Among St. Jerome’s four principles, a certain tendency of priority is evident, with the highest emphasis placed on maintaining the sense. Following this, an elegant and proper translation takes precedence over the translation of Vetus Latina or a word-for-word translation, and the translation of Vetus Latina was preferred to a word-for-word translation. However, this tendency is not absolute and may be reversed in some passages. Understanding these principles allows for a proper evaluation of St. Jerome’s Vulgate Bible and sheds light on the influence of the Classical tradition on St. Jerome.