(1) Classical writers in the New Testament/early Church period.

“His [Celsus] discussion of NT texts will be treated below, but one can say at the outset that Celsus does not bother to give verbal quotations from OT or NT texts with some rare exceptions. He quotes Jesus' words without identifying Matthew (2.24 [154,9 Koet.] is close to Mt 26:39)... In 6.16 (86,13-14 Koet.) he quotes Mt 19:24 par. He also quotes a Gnostic Christian who knows Gal 6:14 without mentioning Galatians (5.65 [68,10-11 Koet.]):… He approaches Paul's words in 1 Cor 3:19 in 6.12 (82,12 Koet.) …. …Borret identifies twenty one references to texts from Matthew by Celsus, no references to Mark, eight references to Luke (most of which are parallel to Mt), four references to John, one to 1 Cor 10:20, and one to Col 2:18. Jesus is one of the few NT figures Celsus is willing to call by name.” [HI:INTGRP, 25]

“These [Greco-Roman] works were selected over others for a variety of reasons. All the authors are relative contemporaries of Paul, spanning the period from just before to just after his time. Each represents a different type of literature: Strabo writes a semi-scholarly treatise on a "scientific" subject; "Longinus" offers an exercise in literary criticism designed to promote a particular style of writing; Heraclitus puts forward a passionately rhetorical defense of Homer against the accusations of certain detractors; and Plutarch's two essays represent first, a moral critique of poetry in general (and Homer in particular), and secondly, a personal letter of condolence to a friend grieving over a lost child. Finally, each author employs the Homeric materials in a somewhat different fashion, permitting the study of a reasonable variety of citation techniques within a narrow range of texts… A second point of note concerns the manner in which various authors incorporate citations into the body of their texts. Even more than Paul, the Greco-Roman writers examined here exhibit a high degree of flexibility and originality in the way they merge quotations into the developing flow of their own compositions. To be sure, certain more or less formulaic expressions do appear on occasion, usually in combinations that include the words phasi, legei, and heterothi (…). Linking back-to-back citations by kai, kai palin, or some similar short phrase is also a common practice. Far more common, however, are those instances where the author uses his own words to integrate the citation in a creative manner into its new literary context. Often this means omitting every explicit indication that a quotation is even being offered: the reader is expected to recognize the verse as a quotation by its metrical qualities, its familiar content, or both. In many cases the author assumes that the reader will be familiar enough with the original text to supply its precise context - yet another indication of just how deeply the Homeric texts had become engraved upon the corporate psyche. [HI:PATLOS, 272ff]

(2) NT use of the Old Testament

“In other places, Paul quotes biblical texts virtually word-perfect with no indication to his readers that a citation is even present (e.g., Rom 2.6; 1 Cor 5.13, 15.32, 2 Cor 13.1).” [HI:PATLOS, 33]

“This conclusion is obvious if sufficient attention is given to the amount of the OT embedded in the NT. The OT has provided the words and ideas for much of the NT. Unless one has a Bible that prints OT quotations in bold print, this may not be easily seen, for the NT writers often weave the OT words into their own without indicating they are borrowing from the OT. One Bible that does use bold print for NT passages that explicitly use OT words reveals that there are over 400 such texts. Almost half of these are introduced by a statement like “Scripture says” to draw attention to the fact that the authority and thought of the OT is being implemented. For the others, however, the OT words are woven into the fabric of the author’s own statement. … Matthew quotes or consciously reflects the wording of OT passages about 62 times, almost half of which have an introductory formula. The Book of Revelation, on the other hand, never quotes the OT and never has an introductory formula but is probably more dependent on the OT than any other NT book. The Book of Hebrews quotes or consciously reflects the OT about 59 times, again half of which have an introductory formula, but the Gospel of John does so only 18 times, nearly always with an introductory formula. However, the allusions to the OT are present on virtually every page of John’s Gospel, so much so that some scholars have argued that he has modeled his account on the exodus narrative, the Jewish feasts, or OT persons and images.” [Baker Ency of the Bible]

(3) Other Jewish writings of the Period

“Leroy Hammill, in studying biblical interpretation in the Apocrypha and the Pseudepigrapha, notes that these books contain almost no exegesis per se (i.e. formal biblical commentary) but that the results of such exegesis can be inferred from their use of the Old Testament, especially in direct quotations. Such quotations are not always easy to detect, since they are 'nearly always filled right in with the author's own words without any mention that Scripture was being quoted'. [OT:SQVP,147]

“(from Qumran) Every reader of the Manual of Discipline (1QS) is impressed with the wealth of biblical language that permeates every quarter of this important text. It thus comes as something of a surprise to discover only three explicit quotations within the eleven columns of this diverse work. Clearly the direct citation of biblical texts played almost no role in the literary and rhetorical aims of the author(s) of this document. The few quotations that do occur bear out this conclusion: one agrees fully with the Masoretic text (5.17), another diverges from it only in the characteristic Qumran elimination of the divine name (8.14), and the third shows only one minor deviation that can be seen also in the Septuagint (the addition of kol in 5.15). The only feature of note is a further instance of "limited selection" in5.15. … War Scroll (1QM) … Like the Manual of Discipline, the War Scroll resounds with biblical language. Nevertheless, explicit quotation remains the exception rather than the rule in IQMas in 1QS. Only four times in the entire document (all in the hortatory sections of columns ten and eleven) is a specific biblical text adduced with an introductory formula, and this always with the stereotyped la’mor. [HI:PATLOS, 300,301; but no author is given, even in those cases.]

“Thirdly, the use of introductory formulae is apparently a historical development, since they appear only in the latest apocryphal books and with increasing frequency at Qumran. Since they are not employed every time a passage from the Old Testament is repeated almost verbatim by a later writer, even at Qumran, it is wrong to demand such a formula for 'true quotation' to be present. It is not clear what their use indicates about an author's attitude toward the Old Testament. Since formulae never accompany the Hodayoth citations, it may be that their use is governed by the author's purpose within a given text or passage. The infrequency of explicit quotations also may be due in part to stylistic or generic requirements. [OT:SQVP, 169f]