In a follow up to my last post on Ambrosiaster and works of the law, here is what I’m thinking about such works:
The phrase “works of the law” (ex ergōn nomou) has prompted a sway of debate as to its meaning (see Rom 2: 15; 3:27-38; Gal 2:16; 3:2, 5, 10). At the risk of simplicity, the main options appear are:
(1) The ceremonial law (e.g., Jerome, Pelagius);
(2) The social boundary markers of the law with specific reference to circumcision, dietary laws, and Sabbath (e.g., New Perspective on Paul);
(3) Keeping the law with a legalistic spirit (e.g., Daniel Fuller);
(4) The works prescribed by the law (e.g., Luther, Calvin).
The phrase is hard to discern because it is incredibly rare in Jewish usage. On the one hand, the “works of the law” seems to mean no more than the “works which the law requires” and embraces all 613 commandments of the Torah. On the other hand, the works of the law law cannot be divorced from its social context whereby faithful observance of the law would mean a separation from Gentile social-spaces and require the maintenance of boundaries to preserve the purity of Jewish communities. On a third hand (if I can borrow one), the phrase also seems to reflect Jewish sectarian disputes about halakhah or the precise manner in which the Torah was to be interpreted and lived. As such, I prefer to describe the “works of the law” as referring to the Jewish way of life as codified in the Torah.If that is the case, what Paul appears to be saying in Romans 2-3 is that taking up Torah-observance, in whole or in part, even to the point of proselytizing and joining a Jewish community, will not constitute a “righteousness” that avails before God. A proper reading of the Torah discloses its inability to deliver persons from the evil within themselves. Furthermore, the Torah really serves to declare God’s righteous contention against all sinners and transgressors, i.e., the law brings “consciousness” or “knowledge” of sin.
 Cf. e.g., 4QMMT 31; 1QS 5.21, 6.18; 2 Bar. 57.2.
 Interestingly Ambrosiaster (28) defines the “law” in 3:21 as “law of the sabbath, the circumcision, the new moon, and revenge” and in 3:28 he defines “works of the law” as “circumcision or new moons or the veneration of the sabbath.”
 Watson, Beyond the New Perspective, 19. I’ve also argued elsewhere (Michael F. Bird, “What if Martin Luther Had Read the Dead Sea Scrolls? Historical Particularity and Theological Interpretation: Galatians as a Test Case,” JTI 3 : 117) that while works of the law means “works which the law requires” it is impossible to eliminate the social and ethnic connotations of the phrase: (1) A cursory glance of Menahem Stern’s Greek and Latin Authors on Jews and Judaism shows how pagan authors were confused and disgusted by Jewish separation from Gentiles demanded by their distinctive way of life (e.g., Tacitus, Histories 5.5); (2) Several pieces of literature assume a default setting of Jews separating from the Gentiles (e.g., Acts 10:28; Gal 2:11-14; Ep. Arist. 139); (3) It is surely interesting that in the second century when Justin Martyr discusses the Torah with Trypho the Jew that the very first point that Justin brings up is Jewish separation from Gentiles (Dial. Tryph. 10); and (4) Without reducing Paul’s remarks about “works” to Jewish attitudes of exclusion and superiority, it is hard to avoid the fact that in Romans and Galatians Paul addresses the question of Jewish boundary makers and rites of passages vis-à-vis Gentile Christians.