It is common to refer to Papias for the early tradition about the authorship of the gospels of Matthew and Mark; sometimes a person might get a bit more sophisticated and refer to the Elder, presumably John, to whom Papias attributes the tradition. But neither of these attributions is the complete picture:
Only the tradition about Mark is explicitly attributed, by Papias himself (if the quotation is accurate), to the Elder. The tradition about Matthew is attributed to Papias; no intermediary is implied in the quotation itself.
This distinction raises the possibility that John the Elder referred only to Mark; Papias, coming a bit later, quoted the Elder concerning Mark and then added his own information concerning Matthew. That Eusebius should have placed the traditions in this order, Mark and then Matthew, suggests to me that this is the order in which he found them in Papias, since the church at large held that Matthew had been composed first; this point stands regardless of who is to be credited with the Matthean one. But this order is also in harmony with the possibility that Papias is quoting the Elder first and then adding his own knowledge of texts which the Elder had not mentioned. And Matthew may not stand alone, since Eusebius in 3.39.17 credits Papias with knowing a story which he says was found in the gospel according to the Hebrews. Assuming that the texts Papias is referring to were in Greek, a Greek gospel of Matthew and also the so called gospel to the Hebrews may be what Papias has in mind when he writes that "each interpreted them as he was able." The wording implies at least two; if there are others, then Eusebius does not name them for us (possibly because Papias did not name them either).
Now, I have laid out a conjecture before on this forum for the existence of an early gospel of Mark in which Levi was called in Jericho, in that gap at Mark 10.46. It has long been suspected that the pericopes in Mark 2.1-3.6 were compiled artificially into a series of "controversy stories," and my suggestion was that the story of the calling of Levi, before it found a place among the controversy stories, was originally situated in Jericho. I also put forth reasons to think that another early text, which I labeled either as L1 or L2 for the sake of convenience, had left the calling of Levi in Jericho but had renamed him as Matthias (and, of course, our canonical Luke renames him as Zacchaeus). I did not specify at the time whether Zacchaeus had come before Matthias or vice versa; I specified only that Levi had been the very first, before either of the other two.
My reasoning for Matthias having been named in Jericho was a comment by Clement of Alexandria:
How better to know that Matthias and Zacchaeus might each be the chief publican whom Jesus forgave than to find the same basic story in two different texts, with each text offering a different name for the same character? Instead of leaving the other of the two texts anonymous, I am also prepared to submit that it was the gospel according to the Hebrews:
My proposal is that the gospel of the Hebrews contained only one calling of a publican (unlike our canonical Luke), and that publican's name was Matthias. With only the one calling in the gospel, and that in Jericho, some readers might think that Matthias and Zacchaeus are supposed to be the same person, while others might think that Matthias and Levi are supposed to be the same person, thus explaining both Clement's and Didymus' comments above.
If this reconstruction is correct, then both the gospel of Matthew and the gospel of Matthias have made the same basic move. Recall that Matthew and Matthias are just two variants of the same Hebrew name: מַתִּתְיָהוּ Matityahu = Ματταθίας = Ματθαῖος/Μαθθαῖος. Well, each of these gospels has replaced poor Levi with a Matityahu; Matthew and Matthias were generally kept separate in Greek, but both wound up being important tradents of gospel information, and I think that this is because they originated as the same guy. The variant in the gospel of the Hebrews was Matthias, while that in the gospel of Matthew was Matthew, and after that the two went their separate ways.
The purpose of this renaming of Levi was, I suspect, exactly as Richard Bauckham surmised:
And the gospel of the Hebrews made exactly the same move, thus making itself, like the gospel of Matthew, a claimant to the label of "the text which Matthew, author of the Logia, had penned." This shared move would explain how Papias knows of at least two anonymous authors, each of which had translated the fabled Logia "as he was able." It would also help to explain the patristic confusion between "the original gospel of Matthew in Hebrew" and the gospel according to the Hebrews.
Finally, long before I had written about Matthew, Matthias, Levi, and Zacchaeus, I had looked into the parable of the talents (Matthew) or pounds (Luke) and concluded that the parallel parable recounted by Eusebius as coming from the gospel according to the Hebrews may have been the original version, which both Matthew and Luke had altered. When I did my work on Matthias in Jericho I did not have the gospel of the Hebrews in mind (hence the clumsy labels L1 and L2), but it is interesting how, once I plug in the gospel of the Hebrews for L1 on my first (and preferred) option in that thread, simultaneously removing the notion that this text had a calling both of Matthias and of Levi (which I now think only Marcion/Luke later did, conflating the gospel of the Hebrews and that of Mark), the implied textual relationships are mutually compatible:
(I am arranging Marcion first, and then Luke, in a direct line, but this is only for convenience; the reverse relationship or a more complex relationship involving a common source would fill the same role for my purposes on this thread.)
And... these relationships are also compatible with a reconstruction by which the Elder mentioned only Mark, whereas Papias mentioned both Matthew and Mark and also knew, and perhaps mentioned, the gospel of the Hebrews; the texts potentially stack in roughly that order.
I do not know whether I am on the right track or not, but I am liking how some of the seemingly disparate details seem to dovetail.
Ben.