Here there will be three classes of quotation more or less directly in point:  (1) the quotations from the Old Testament in the New; (2) the quotations from the Old Testament in the same early writers whose quotations from the New Testament are the point in question; (3) quotations from the New Testament, and more particularly from the Gospels, in the writers subsequent to these, at a time when the Canon of the Gospels was fixed and we can be quite sure that our present Gospels are being quoted.

This method of procedure however is not by any means so plain and straightforward as it might seem.  The whole subject of Old Testament quotations is highly perplexing.  Most of the quotations that we meet with are taken from the LXX version; and the text of that version was at this particular time especially uncertain and fluctuating.  There is evidence to show that it must have existed in several forms which differed more or less from that of the extant MSS.  It would be rash therefore to conclude at once, because we find a quotation differing from the present text of the LXX, that it differed from that which was used by the writer making the quotation.  In some cases this can be proved from the same writer making the same quotation more than once and differently each time, or from another writer making it in agreement with our present text.  But in other cases it seems probable that the writer had really a different text before him, because he quotes it more than once, or another writer quotes it, with the same variation.  This however is again an uncertain criterion; for the second writer may be copying the first, or he may be influenced by an unconscious reminiscence of what the first had written.  The early Christian writers copied each other to an extent that we should hardly be prepared for.  Thus, for instance, there is a string of quotations in the first Epistle of Clement of Rome (cc. xiv, xv)—­Ps. xxxvii. 36-38; Is. xxix. 13; Ps. lxii. 4, lxxviii. 36, 37, xxxi, 19, xii. 3-6; and these very quotations in the same order reappear in the Alexandrine Clement (Strom. iv. 6).  Clement of Alexandria is indeed fond of copying his Roman namesake, and does so without acknowledgment.  Tertullian and Epiphanius in like manner drew largely from the works of Irenaeus.  But this confuses evidence that would otherwise be clear.  For instance, in Eph. iv. 8 St. Paul quotes Ps. lxviii. 19, but with a marked variation from all the extant texts of the LXX.  Thus:—­

Ps. lxviii. 18 (19).

[Greek:  Anabas eis hupsos aechmaloteusas aichmalosian, elabes domata en anthropon.]

[Greek:  Aechmaloteusen ... en anthropon] [Hebrew:  alef], perhaps from assimilation to N.T.

Eph. iv. 8.

[Greek:  Anabas eis hupsos aechmaltoteusen aichmalosian, kai edoke domata tois anthropois.]

[Greek:  kai] om. [Hebrew:  alef]’1, A C’2 D’1, &c.  It.  Vulg.  Memph. &c.; ins.  B C’3 D’3 [Hebrew:  alef]’4, &c.