Thanks for writing this up! What follows is kind of a gut reaction, so if I'm fuzzy or confused, let me know.
I think I may see where our approaches are diverging, and it has to do with the meaning of fulfill. I'm not looking at it in the sense of finish up, or what you call the messianic and eschatological endpoint of the law. I think of fulfillment as complete obedience to the law (and that complete fulfillment is what righteousness is). Someone who does what the law commands has fulfilled the law, and that would include anyone before Jesus as well (though, that wouldn't happen...for Pauline reasons). So I don't think that fulfillment in its basic sense as a concept requires a messianic or eschatological endpoint (though that is important, but perhaps for different reasons). As such, I think that means what Jesus offers here isn't a unique messianic interpretation of the Torah which is binding on Christians as if there was a sense prior to Jesus that it could be interpreted another way. I think that approach starts us off on the wrong foot and suddenly we have to figure out how to reconcile Jesus's interpretation of the law from our "independent" interpretation of the law (the Torah actually says X, but Jesus interprets it as Y; not saying you do that, but I do see that commonly employed). Instead, what I think Jesus is doing is explaining HOW to fulfill the law. It's not by doing each command or avoiding each prohibition, but by having a transformed heart. The commands, then, are not ends in themselves, but they point to something more fundamental. They are examples of an underlying order that God has baked into his creation. The commands point us to that underlying reality, but that is all they can do. Only a good heart (Matthew's contrast between the good heart and evil heart is pronounced) will bear good fruit, namely, fulfill that underlying reality to which the law points. I think that is what Jesus is teaching in this first section of the Sermon on the Mount.
This is, perhaps not coincidentally, what I think Paul is saying in a passage like Romans 8. Matthew speaks less in terms of how the Holy Spirit enables us to do that (because the New Covenant is tied to the promise of the Spirit and the New Heart), but I think they have the same general approach .
So my short comment/reply would be to say that I think my sense of 'fulfil' is consistent with how Matthew talks about fulfilment of the Law and Prophets throughout the gospel, and it would be those passages (especially his quotations?) that we need to look at.
Sorry, I made it sound like I wanted all cases of fulfillment to be in the sense of obeying the Law. That would be reductionistic and wrong. I think Matthew uses fulfill in more than one sense, and context determines which is relevant. David Turner, in his commentary on Matthew, identifies three, which he calls ethical (3:15; 5:17), historical (1:22; 2:15, 17, 23; 13:14, 35; 23:32; 27:9), and prophetic (=predictive, e.g., 4:14; 8:17; 12:17; 21:4; 26:54, 56), though these are not mutually exclusive. I don't exactly like these terms, but as a heuristic, they work. What Turner calls "ethical" in 3:15 (Jesus' baptism) and 5:17 (our example in question) is the sense that I'm identifying as obeying the law (note the connection with righteousness in both passages as well as 5:18-20 emphasizing the perpetual nature of the Law).
Yes, Jesus doesn't just obey the law completely but does so AS the eschatological messiah. I'm not denying that that is part of what is going on here. But I think that the use of fulfill here is grounded primarily in the "obedience" sense. To fulfill the law is to obey it. In fact, Paul uses fulfill in relation to the law in just that sense in Rom 8:4; 13:8; and Gal 5:14 (and perhaps not coincidentally Romans and Galatians are concerned with he question of righteousness!). So, I don't deny that there is a real sense in which Jesus' perfect obedience to the Law (as Covenant, to use Rosner's categories) fulfills it by bringing it to completion in his death and resurrection initiating the new covenant. But I just don't think that is Matthew's point here. Indeed, 5:18-20 sets up what follows to answer the implied question: how can one's righteousness (=obedience to the Law) exceed (πλεῖον, and so quantitatively) the righteousness of the scribes and the Pharisees? He tells us in 5:21-48: by getting to the root of the problem, an evil heart, and having a good heart, one fulfills not only the specific commands (or avoids the prohibitions) of the Law, but one actually fulfills more than the Law commands. I suspect because it functions not only in the situations imagined by the Law, but even in those that are not imagined by the Law. Kind of like how a genus includes more than a species, the good heart (or, if you will, the Love command, the "genus") will fulfill even greater righteousness than what the Law ("species") commands.
Thanks for writing this up! What follows is kind of a gut reaction, so if I'm fuzzy or confused, let me know.
I think I may see where our approaches are diverging, and it has to do with the meaning of fulfill. I'm not looking at it in the sense of finish up, or what you call the messianic and eschatological endpoint of the law. I think of fulfillment as complete obedience to the law (and that complete fulfillment is what righteousness is). Someone who does what the law commands has fulfilled the law, and that would include anyone before Jesus as well (though, that wouldn't happen...for Pauline reasons). So I don't think that fulfillment in its basic sense as a concept requires a messianic or eschatological endpoint (though that is important, but perhaps for different reasons). As such, I think that means what Jesus offers here isn't a unique messianic interpretation of the Torah which is binding on Christians as if there was a sense prior to Jesus that it could be interpreted another way. I think that approach starts us off on the wrong foot and suddenly we have to figure out how to reconcile Jesus's interpretation of the law from our "independent" interpretation of the law (the Torah actually says X, but Jesus interprets it as Y; not saying you do that, but I do see that commonly employed). Instead, what I think Jesus is doing is explaining HOW to fulfill the law. It's not by doing each command or avoiding each prohibition, but by having a transformed heart. The commands, then, are not ends in themselves, but they point to something more fundamental. They are examples of an underlying order that God has baked into his creation. The commands point us to that underlying reality, but that is all they can do. Only a good heart (Matthew's contrast between the good heart and evil heart is pronounced) will bear good fruit, namely, fulfill that underlying reality to which the law points. I think that is what Jesus is teaching in this first section of the Sermon on the Mount.
This is, perhaps not coincidentally, what I think Paul is saying in a passage like Romans 8. Matthew speaks less in terms of how the Holy Spirit enables us to do that (because the New Covenant is tied to the promise of the Spirit and the New Heart), but I think they have the same general approach .
So my short comment/reply would be to say that I think my sense of 'fulfil' is consistent with how Matthew talks about fulfilment of the Law and Prophets throughout the gospel, and it would be those passages (especially his quotations?) that we need to look at.
Sorry, I made it sound like I wanted all cases of fulfillment to be in the sense of obeying the Law. That would be reductionistic and wrong. I think Matthew uses fulfill in more than one sense, and context determines which is relevant. David Turner, in his commentary on Matthew, identifies three, which he calls ethical (3:15; 5:17), historical (1:22; 2:15, 17, 23; 13:14, 35; 23:32; 27:9), and prophetic (=predictive, e.g., 4:14; 8:17; 12:17; 21:4; 26:54, 56), though these are not mutually exclusive. I don't exactly like these terms, but as a heuristic, they work. What Turner calls "ethical" in 3:15 (Jesus' baptism) and 5:17 (our example in question) is the sense that I'm identifying as obeying the law (note the connection with righteousness in both passages as well as 5:18-20 emphasizing the perpetual nature of the Law).
Yes, Jesus doesn't just obey the law completely but does so AS the eschatological messiah. I'm not denying that that is part of what is going on here. But I think that the use of fulfill here is grounded primarily in the "obedience" sense. To fulfill the law is to obey it. In fact, Paul uses fulfill in relation to the law in just that sense in Rom 8:4; 13:8; and Gal 5:14 (and perhaps not coincidentally Romans and Galatians are concerned with he question of righteousness!). So, I don't deny that there is a real sense in which Jesus' perfect obedience to the Law (as Covenant, to use Rosner's categories) fulfills it by bringing it to completion in his death and resurrection initiating the new covenant. But I just don't think that is Matthew's point here. Indeed, 5:18-20 sets up what follows to answer the implied question: how can one's righteousness (=obedience to the Law) exceed (πλεῖον, and so quantitatively) the righteousness of the scribes and the Pharisees? He tells us in 5:21-48: by getting to the root of the problem, an evil heart, and having a good heart, one fulfills not only the specific commands (or avoids the prohibitions) of the Law, but one actually fulfills more than the Law commands. I suspect because it functions not only in the situations imagined by the Law, but even in those that are not imagined by the Law. Kind of like how a genus includes more than a species, the good heart (or, if you will, the Love command, the "genus") will fulfill even greater righteousness than what the Law ("species") commands.