This new and revolutionary edition of Origen's Commentary on Matthew is based on the version in Codex Sabaiticus 232, the most important of all because, unlike the 24 codices consulted by Erich Klostermann in his standard edition of 1941, it contains not only episodic 'passages', but also unique flowing text. The same codex also reveals for the first time how heavily Origen's work was used, and sometimes copied to the letter, by ancient authors. Against the prevailing opinion, Professor Panayiotis Tzamalikos incontrovertibly confirms his long-standing thesis that the Commentary on Matthew is much later than the Contra Celsum. Origen's detractors, both ancient and modern alike, in order to show how much of a 'heretic' Origen was, point the finger at a garbled, untrustworthy, and heavily interpolated Latin rendering of his De Principiis, whereas reference to his Commentary on Matthew has always been scarce, and Pamphilus' illuminating and documented Apology for Origen is normally paid almost no attention. The author demonstrates that, unless the correlations of Origen's work to both Greek philosophy and subsequent Patristic literature are knowledgeably delved and brought to light, it is impossible to recognise the real Origen, which has far too little to do with current allegations concerning pivotal aspects of his thought. By means of his commentary on this Greek text, P. Tzamalikos, as he did with his previous books, casts light on the widespread and multiform miscomprehension of Origen's fundamentals, and demonstrates that this is a terra still calling for informed and unbiased exploration.