1. Thaddeus/Judas/Lebbaeus in Matthew 10
There is mixed opinion regarding the list of twelve apostles (10:1-4), on a number of issues. First, the question of Thaddeus/Judas/Lebbaeus. All commentators I surveyed for this passage (mainly Davies and Allison, France, Hagner, and Blomberg) see Thaddeus as the original reading, with which I agree. There are numerous theories as to how the Lebbaeus variant arose. One theory is that Labbaeus is the copyist’s attempt to insert Levi into the account (France, 374; Davies/Allison, 156 n.52). This theory would appear to take Matthew the tax collector as a different individual than Levi, an idea to which I am not well disposed. Also, I do not understand how one could posit such an idea, and meanwhile see “the toll collector†as an interpolation to explain the story of 9:9 (Davies/Allison, 145). Another ideas is that Thaddeus and Lebbaeus are both come “from the Hebrew taday (breast) and leb (heart)†(Blomberg, 169; cf. Davies/Allison, 156). Alternatively, I did not find any assertion by Hagner on this variant (Hagner, 263). The second idea, the Hebrew-names hypothesis, seems plausible to me. Davies/Allison gives one of the most interesting pieces of evidence I have seen for this: the inclusion of a man named tÈdầ on a talmudic list Jesus’ disciples (Davies/Allison, 156). If true, it would seem to give a possible glimpse into a tradition about the twelve, as well as a possible glimpse at the practices of Christian scribes (who either knew Hebrew or were aware of the tradition of the name).
The issue of this name would not be complete without an attempt to explain why Mark and Matthew have Thaddeus, while Luke (and John) has Judas. The general tendency is to see Judas as the same person as Thaddeus/Lebbaeus, but without explaining the variation in names (Davies/Allison, 156, following Jeremias; Hagner, 266). France fails to assert even this much (France, 374). The most assertive suggestion comes from Blomberg: Judas was his real name, while the other two designations are his nicknames (Blomberg, 169).
While I would not want to be overly speculative on this, I do wonder how Luke and John came to preserve Judas, while Matthew and Mark designate him as Thaddeus, and early traditions point to an additional name of Lebbaeus. This plays into the overall issue of interdependence. If Matthew followed Mark (Hagner, 264; Davies/Allison, 145), then the origin of the “nickname†tradition would most likely have been Peter, who was well-acquainted with Judas-Thaddeus on an intimate level. Davies/Allison see the distinct possibility that Q material comprises part of the list (Davies/Allison, 145); but in my mind, this would not explain why Matthew would keep the (possibly) Petrine-origin Thaddeus, a title of affection. Alternatively, if Matthew was indeed written by Matthew, then the name Thaddeus need not depend upon the connection to Peter, since Matthew would have known Judas-Thaddeus. It makes more sense to me to say that Judas-Thaddeus was known in the original Matthean community/communities from an early date, and by his affectionate name (and perhaps Origen reflects this, if the Latin translation reflects his knowledge?). Luke and John, however, were writing later, and to a wider audience, and the use of the proper name Judas would simply make more sense.
2. The Message of Jesus in Matthew 10
As for the teaching of Jesus, the commentators who discuss sources tend to see this as a Mark-Q combination by Matthew. Hagner minimizes the role of Mark, and allows for the presence of orally transmitted materials (Hagner, 268). Keener seems to think that Mark knew Q, and that Matthew uses a Mark-mediated-Q (e.g. Keener, 319)! Davies/Allison construct an entire Q discourse (or the “contours†of one) based on their redactional analysis (Davies/Allison, 164). They then speculate that Paul knew of a Q-like collection of sayings. Not having done an analysis of verbatim agreement between Luke and Matthew, I cannot speak to this definitively. If Q = oral tradition (approximately speaking), and Matthew took form as a sermonic repetition of this same material, it is hard to saw which came first, since they are all probably in flux with one another.
Regardless of source(s), the significance of the discourse seems to be addressed both to Jesus’ day and to a later time. Keener points out elements (e.g. pagan courts) that were not a factor in Jesus ministry (Keener, 313), at least as far as we know. However, we should not go as far as our continental friends, who see this as a product of a later time with little basis in pre-Easter instruction (e.g. Schweizer, 236; cf. Luz, Schnakenburg). Preferable is the notion that the historical core is the teaching of Jesus, and that Matthew presented this in a way that allowed it to continue in its applicability; though, France cautions, “mutatis mutandis,†the necessary changes have to be made (France, 380). Indeed, the continued applicability of the discourse is modeled by the example of Paul in his epistles (his explicit words), as well as the picture of Paul in Acts (in explicit action, e.g. shaking the dust off when leaving a city). Certain conditions should dictate the applicability. The least we can do is to respect such social constructs presupposed in the discourse as we probe it for theological meaning. Persecution is the most obvious one; and where persecution is absent, the applicability of this discourse becomes less apparent. In today’s world, where un-persecuted, salaried ministers are common, any applicability would seem to be frozen for another day.