The writings of Irenæus, Tertullian, Clement of Alexandria, and Origen, belonging to the latter part of the second century, and the beginning of the third, contain a large body of quotations from the Gospels and Epistles. The works of Origen alone may, with scarcely any exaggeration, be said to be equivalent to an additional manuscript of the New Testament. He died about A.D. 253 or 254, and during his entire life gave himself with a most indomitable perseverance to Biblical studies. In addition to an elaborate revision of the Greek text of the Septuagint, upon which he spent eight and twenty years, but of which unhappily some fragments only have reached us, he composed expositions or homilies upon the larger part of the books of the Old and New Testaments. Of these some very considerable portions have come down to us, and as his expositions on the Old Testament abound in quotations from the New, the number of passages from the latter found in his writings is very large. Of writers belonging to the fourth century we have commentaries in Greek by Chrysostom and Didymus, and in Latin by Hilary of Rome, and Jerome; and, in addition, extensive theological treatises, involving numerous appeals to the Scriptures, by Athanasius, Ambrose, Basil, Epiphanius, and the two Gregorys. In the following century we have the Greek commentaries of Theodore of Mopsuestia and Theodoret; the commentary of Pelagius on the Epistles of Paul; and the voluminous writings of Augustine, including commentaries on the Psalms, the Sermon on the Mount, John’s Gospel and Epistles, and Paul’s Epistles to the Romans and Galatians, together with a large number of Homilies on various parts of Scripture. These numerous writings form a mine of wealth to the Biblical critic; but it is a mine that has only been diligently worked in comparatively recent years. Much wearisome toil has been necessary in bringing to light its treasures, and these were either overlooked or neglected by the earlier editors of the Greek New Testament.