Wondering what Herman Bavinck said about the Mosaic Covenant with regards to it being a republication of the Covenant of Works I looked into his section on the Mosaic Covenant in his four volume Reformed Dogmatics, and I found nothing on the subject. So... Since the subject regarding the republication of the Covenant of Works at Sinai is really the subject of the active obedience of Jesus, and what he is being obedient to (his active obedience now, his passive obedience was his voluntary death on the cross) I went to that section of his great Reformed Dogmatics, and...a direct hit! Here it is:
"Even more, as a human being Christ was certainly subject to the law of God [i.e. the laws given on Sinai to Moses, which is the context of the passage] as the rule of life; even believers are never exempted from the law in that sense. But Christ related himself to the law in still a very different way, namely, as the law of the covenant of works. [...] He submitted himself to the law of the covenant of works as the way to eternal life for himself and his own." Bavinck, Reformed Dogmatics, Volume Three, page 379
I.e. as the Second Adam. Jesus came to fulfill what the first Adam failed to fulfill. So, was Jesus then supposed to come and 'not eat of the tree of the knowledge of good and evil'? Well, yes, in this way: that command not to eat of that tree was part of the Covenant of Works in the Garden. And that covenant, the Covenant of Works in the Garden, was *republished* (not 'reestablished' but *republished*) on Sinai in elaborated form. Jesus also had to be born under the law, and so that law was *republished* on Sinai so that the world throughout historical time would know he had been born under the law and fulfilled all of that law to a 't'.
Bavinck assumes all this in the statement above. And guess what? Bavinck didn't think fallen man could save himself by his works. Bavinck was kind of 'onto that.' As was Thomas Boston, and Witsius, and Brakel, et al.
There is *one way* to be saved: works. Either your own (good luck with that) or Jesus Christ's appropriated by faith. Jesus fulfilled the Covenant of Works (what Adam knew as the command to not eat of the tree of the knowledge of good and evil, which he failed to follow, and what Jesus knew as the laws given to Moses on Sinai [that Jesus! gave to Moses on Sinai], which were a republication of the Covenant of Works given to Adam in the Garden yet given in much elaborated form for their typology to teach individual Israelites and all gentiles that only faith in the promise [looking forward to the Incarnation and cross] or faith in the fulfillment [looking backwards to the Incarnation and cross] of Christ's work saves).
National Israel (the entity, not individual Israelites) which was a prototype of Jesus Christ was the object of the contemporary works elements of the laws given on Sinai (do this and stay in the land, don't do this and get booted out of the land). National Israel was a unique player in God's plan of redemption. As unique a player as pre-fall Adam and Jesus Christ Himself. National Israel's history itself was the substance of the revealed Word of God. National Israel had the task not only to conceive and protect the oracles of God but to keep the royal bloodline pure from Adam to Christ (the harsh laws are for this). National Israel was a unique player in God's plan of redemption. Individual Israelites were saved by faith in the coming Messiah just as we are saved by faith in the already come Messiah, but National Israel the entity was a different thing, a unique player with unique tasks given them by God to fulfill in God's plan of redemption. This is why Paul struggles in Romans to articulate just why his people are both unique and yet the same as everyone else when it comes to salvation.
Enough said. Bavinck clearly assumes the republication of the Covenant of Works on Sinai in the passage above.