[Footnote E: There is a manuscript copy of this epistle in connection with a copy of the New Testament entire, dating back to the fourth century, now in the St. Petersburg Library. It was found by Tischendorf in the convent of St. Catherine on Mount Sinai, in 1859, and is known as the Sinaitic Manuscript--the oldest one in existence.] In this epistle appears the following remarkable passage: "Let us, therefore, beware lest it come upon us, _as it is written_; There are many called, few chosen." From the expression, "as it is written," we infer, with certainty, that at the time when the author of this epistle lived, there was a book extant well known to Christians, and of authority among them, containing the words "many are called, few chosen." Such a book is our present Gospel of St. Matthew, in which this text is twice found,[F] and found in no other book which existed in those days; therefore Barnabas must have referred his readers to Matthew's Gospel. Furthermore, the writer of the epistle was a Jew. The phrase, "It is written," was the very form in which the Jews quoted their scriptures. Hence, it follows that he would not have used this phrase, and without qualification, of any books but what had acquired scriptural authority. So that while the quotation "many are called, few chosen," confirms the existence of Matthew's Gospel; the expression "It is written," gives to it the authority or dignity of scripture. [Footnote F: Matt. xx: 16; xxii: 14.] There are other passages in the epistle which are the same in sentiment as some of the passages in Matthew,[G] some in which we recognize the same words. For example, "Give to every one that asketh thee;" and he says that Christ chose as his apostles men who were great sinners that he might show that he came, "not to call the righteous, but sinners to repentance." [Footnote G: Matt. v: 42; ix: 13.] There is also extant an epistle of Clement, bishop of Rome, whom the ancient writers without doubt or scruple assert to have been the Clement whom Paul mentions in Phil. iv, 3.[H] This epistle is spoken of by the early Christian writers as an epistle acknowledged by all. Of it Irenaeus says (writing in the second century) it was "written by Clement, who had seen the blessed apostles, and conversed with them, who had the preaching of the apostles still sounding in his ears, and their traditions before his eyes." Dionysius, bishop of Corinth (the epistle is addressed to the Church of Christ) says, about the year 170 A. D., that the epistle of Clement "had been wont to be read in that church from ancient times."[I] [Footnote H: "With Clement also, and with other my fellow-laborers whose names are written in the book of life."] [Footnote I: A copy of this epistle dating back to the fifth century, is connected with the Alexandrian manuscript of the New Testament now in the British Museum. The manuscript was given to Charles the I. in 1628 by Cyril Lucas, Patriarch of Constantinople.]