Over on Exploring Our Matrix, James McGrath asks Did Matthew use Luke? A Neglected Angle on the Synoptic Problem. It is one of the rarer theories to come up in Synoptic studies and it has no detailed published case from recent times. It has been floated by Martin Hengel (alongside Q) and Ronald Huggins and it is now being explored fully in a PhD dissertation at Dallas Theological Seminary by Robert Macewen. I occasionally get asked myself about this view, presumably because it reverses the direction of dependence for which I argue, in The Case Against Q, and so, perhaps, it helps us to think through the plausibility of the case for Luke's familiarity with Matthew. Since James specifically tags me, as it were, in his post, and since it is difficult to resist a good, old-fashioned Synoptic Problem post, I will make a few comments.
My initial reaction when asked about this is usually simply to say that it's a radically different theory from the one I argue for (it reverses the key thing). Sometimes Q theorists imagine that the big issue for Q sceptics, like me, is dispensing with Q at all costs, and that Luke's use of Matthew just happens to be the way we have chosen to do it. On the contrary, I actually quite like Q, but I am unpersuaded that it exists because I think Luke knew Matthew. In other words, I, and others like me, have not begun from the premise, "We must get rid of Q at all costs. Now, what's the strategy?" We begin from finding Luke's use of Matthew, alongside Marcan Priority, to be more persuasive than the alternatives, and that theory entails the end of Q.
It is true that the rhetoric of our case often brings up Q, Farrer's "On Dispensing with Q", my Case Against Q, Goulder's "On Putting Q to the Test", and so on. But the reason for this is largely strategic. In a world where the vast majority of scholars are wedded to Q, one needs to gain their attention somehow. Would my book have been as successful if I had called it "Luke's use of Matthew", or "The Farrer Theory"? I doubt it.
Let me underline then that I really think that Luke knew Matthew. It's not just a game; I actually think that the Farrer theory explains the data far better than the opposing theories. Like others, I frame the case by arguing with Q theorists because that is the dominant alternative. Similarly, when arguing for Marcan Priority (Case Against Q, Chapter 2; Synoptic Problem: A Way Through the Maze, Chapters 3-4, etc.), I frame the case by arguing with adherents of the Griesbach Hypothesis because they have been the dominant group in the academy that opposes Marcan Priority.
But what about the case for Matthew's use of Luke? Could there be anything in it? Certainly it shares many of the strengths of the Farrer theory; it doesn't struggle over the Minor Agreements; it can explain the close verbatim agreement in double tradition material, and so on. But my main difficulties with it would be the following:
(1) Matthean language and imagery. Here it will be easiest if I borrow from an older blog post. The language, imagery and rhythm of the double tradition material can be Matthean through and through, often to the extent that we would not hesitate to ascribe it to Matthew if it were in Matthew alone. Matthew 3 and Luke 3 provide particularly clear examples:
(a) Matt. 3.7 // Luke 3.7: γεννήματα ἐχιδνῶν, τίς ὑπέδειξεν ὑμῖν φυγεῖν ἀπὸ τῆς μελλούσης ὀργῆς; ("Brood of vipers! Who warned you to flee from the coming wrath?"). Matthew will use this offensive vocative + rhetorical question (labelled an echidnic by Michael Goulder) twice again in remarkably similar forms, 12.34, γεννήματα ἐχιδνῶν, πῶς δύνασθε ἀγαθὰ λαλεῖν πονηροὶ ὄντες ("Brood of vipers! How can you speak good things when you are evil?") and 23.33, ὄφεις, γεννήματα ἐχιδνῶν, πῶς φύγητε ἀπὸ τῆς κρίσεως τῆς γεέννης ("Snakes, brood of vipers! How can you flee from the judgement of gehenna?"). I think we should resist the temptation to play these links down. We are not dealing with everyday phrases. The imagery (snakes' offspring), the rhythm (echidnic) and language (wrath / judgement / gehenna) is strikingly Matthean and tells us in which direction the borrowing is going.
(b) 3.10: πᾶν οὖν δένδρον μὴ ποιοῦν καρπὸν καλὸν ἐκκόπτεται καὶ εἰς πῦρ βάλλεται ("Therefore every tree not producing good fruit will be cut down and thrown into the fire"). Virtually the identical sentence occurs again in 7.19. Once again it is not just the language but also the imagery that is Matthean. Even my introductory New Testament class knows that Matthew's is the Gospel that exploits harvest imagery to the tell the story of judgement and hell-fire. The Matthean apocalyptic scenario, here appearing for the first time in the Gospel, will be repeated at regular intervals: (a) Demand for good fruits / good works; (b) Separation at the Eschaton; (c) Burning of those whose deeds are evil.
(2) Fatigue in the Synoptics: There are several examples of Luke's secondary nature with respect to Matthew in double tradition here -- see "Fatigue in the Synoptics". In researching that article, I found several good examples of Lucan fatigue in double tradition but none of the opposite. One of the best examples is, I think, the Parable of the Talents / Pounds, where Luke makes characteristically Lucan initial changes to the plot of Matthew's parable (ten servants, one pound each -- typically Lucan 10:1 ratio) but then steadily reverts to the Matthean plot, with its three servants ("the other", 19.20) and money (not city) rewards. In the article, I argue that since we know that Matthew is often fatigued in his rewriting of Mark, it is odd that he is apparently never fatigued in the double tradition material. The reason is that Luke is using Matthew, not vice versa.
(3) Luke's Preface with its "many" inclines one towards a Luke who is self-consciously second generation in a way that is less clear with Matthew. The general indications of date also tend to favour a later Luke.
(4) Luke is almost never the middle term: Mark is usually the middle term among the Synoptics, a scenario easily explained on the assumption of Marcan Priority. Sometimes Matthew is the middle term, a fact that Farrer theorists explain on the assumption that these are triple tradition passages where Luke is focusing on Matthew rather than Mark. It would be odd, if Matthew were the third evangelist, that his use of Luke never results in Luke-as-middle-term.
(5) Order: Why would Matthew break up Luke's superb ordering of the sayings, which are in highly appropriate contexts in Luke, tearing every little piece out of its context, only to lump them together in a wooden fashion in huge, unwieldy discourses? Such a theory would only tenable if we had reason to think that Matthew was a crank.
OK, admittedly my number 5 is a parody, but the other reasons sketch some first thoughts on why I would not find Matthew's use of Luke plausible, but the bottom line is that I am already persuaded by another theory that, in my opinion, explains the data much better.