This study deals with the usage of biblical quotations in the Sermon XXI homiletic cycle (published 1663) and the associated collection of relevant parts of the Gospels in the History of the Sufferings (published 1631, 1663, 1757) by Jan Amos Komenský. History of the Sufferings, the pericopal basis of the sermon, is an attempt by Komenský to create a Gospel (Passion) harmony. Komenský made particular use of the Gospel of John as a basis for his narrative conception of the cycle, but he placed it on the chronological axis of the Gospel of Matthew. In some places the text has clearly been abridged and a comparison of the first five chapters of the History of the Sufferings with the text of the Kralice Bible (1601 and 1613) and Manualník (printed 1658) indicate that the text of the History is the shortest in 31% of cases. Sermon XXI is presented in the study as a systematic biblical exegesis, with the emphasis placed conceptually on a four-level exegesis (regular passages of Text, Predictions, Secrets, Morals) and on the establishment of connections between the Old and New Testaments. The biblical quotations are processed by means of data mining, converted into a frequency list and visualized using Voyant Tools and RawGraphs. The frequency analysis indicates that Komenský based his exegesis on three main sources: the prophetic and gnomic verses of the Prophet Isaiah; the conceptual and interpretational verses of the Apostle Paul; and the closest positions of John the Evangelist to Christ and the mysteries of faith (the Gospel, the Letters and the Revelation). The qualitative level of interpretation indicates that Komenský used biblical quotations for a strong Christological version of the text, so the Sermon XXI cycle conveys a consolatory message with an extremely hopeful eschatological emphasis.