By Lee Irons
As my readers know, I hold to republication – the view that the works principle in the pre-fall covenant with Adam was republished at the typological level in the Mosaic economy. Because of this, many ask, “Can you affirm that the Mosaic covenant is an administration of the covenant of grace?” Sometimes the question comes with an attorney-like insistence, yes or no? But this is not a question that can be answered yes or no without qualifications, so here is my best attempt to answer that question.
I think it is valid to say that the Mosaic covenant was a “unique” administration of the covenant of grace. I borrow the term “unique” from Michael Horton who uses it to take account of Paul’s teaching that the law was a temporary guardian until Christ (Gal 3:19-24). As Dr. Horton wrote in a recent four-views book: “The Sinai covenant is a unique administration of the covenant of grace in that it offers a parenthetical-typological system for the church’s adolescence.”
What makes it a unique administration of the covenant of grace is that it has a broad and a narrow aspect. The Mosaic covenant in the broad sense is the Mosaic economy as a whole – that is, the Mosaic economy as continuing the Abrahamic promise (Gal 3:17) and including the sacrificial system, which provided a means of atonement for sin. In that broad sense, the Mosaic covenant is an administration of the covenant of grace. But it also has a narrow aspect, and that is what makes it unique. The Mosaic covenant in the narrow sense is the same as Paul’s term “the law”, the commandments along with the offered blessings for obedience and curses threatened for disobedience (Lev 18:5; Deut 28). In this sense, the law was a temporary guardian until the Seed should come. It was given to drive Israel to Christ and thus for an ultimately gracious purpose.
This language of the broad and narrow sense of “Mosaic covenant” is fairly standard. Dr. Horton says it derives from Calvin:
Calvin himself acknowledges these two senses: “The law has a twofold meaning; it sometimes includes the whole of what has been taught by Moses, and sometimes that part only which was peculiar to his ministration, which consisted of precepts, rewards and punishments … Whenever the word law is thus strictly taken, Moses is by implication opposed to Christ: and then we must consider what the law contains, as separate from the gospel.”
In their helpful book on covenant theology, Michael Brown and Zach Keele explain it this way:
To understand the Mosaic covenant properly, we must view it in both its broad and narrow senses. In its broad sense, the Mosaic covenant is an administration of the covenant of grace … In its narrow sense, however, the Mosaic covenant is a covenant of law … We must first focus on the Mosaic covenant in its narrower sense (that is, law) to fit it properly into God’s overall purpose of the covenant of grace … God gave the strict Mosaic covenant to show Israel and all humanity that no man can be justified by the works of the law (Rom 3:19-20).
Complementary to the broad versus narrow language, there is Meredith Kline’s language of the two layers or strata of the Mosaic economy.
At the same time, Paul affirmed that the Mosaic Covenant did not annul the promise arrangement given earlier to Abraham (Gal 3:17). The explanation for this is that the old covenant order was composed of two strata and the works principle enunciated in Leviticus 18:5, and elsewhere in the law, applied only to one of these, a secondary stratum. There was a foundational stratum having to do with the personal attainment of the eternal kingdom of salvation and this underlying stratum, continuous with all preceding and succeeding administrations of the Lord’s Covenant of Grace with the church, was informed by the principle of grace (cf., e.g., Rom 4:16). Because the Abrahamic covenant of promise found continuity in the Mosaic order at this underlying level, it was not abrogated by the latter. The works principle in the Mosaic order was confined to the typological sphere of the provisional earthly kingdom which was superimposed as a secondary overlay on the foundational stratum.
Now perhaps another follow-up question may arise: “Is the entire Mosaic covenant, in both its narrow sense and in its broader sense, an administration of the covenant of grace?” I can affirm that, but I would want to clarify the two distinct ways in which “the narrow sense” and “the broader sense” are related to the covenant of grace.
I affirm that the Mosaic covenant in the broader sense (the entire Mosaic dispensation or economy) is an administration of the covenant of grace. There are a myriad of ways we see this. We see it in the prologue to the Decalogue, “I am the LORD your God, who brought you out of the land of Egypt.” We see it in the intercession of Moses who appealed to the Abrahamic promise (Exod 32:13; Deut 9:27). We see it in the fact that the two tablets of the law were placed inside the ark of the covenant under the mercy seat (Exod 25:16; 40:20; Deut 10:2, 5; Heb 9:4). But most clearly we see it in the Levitical sacrificial system (the Passover Lamb, the Day of Atonement, etc.), which was a sacramental means of grace by which the Israelites received ahead of time, by faith, the benefits of the work of the Messiah to come. As Kline notes, “Elements of redemptive grace were present in and around the transaction [of the Sinaitic covenant],” and he goes on to cite the prologue of the Decalogue and the location of the tablets under the mercy seat as two chief examples.
But what about the Mosaic covenant in the narrow sense? Can it also rightly be called an administration of the covenant of grace? I can see how it could, but I would want to clarify what that means. It is a foundational Reformed teaching that the law (“Do this and live”) is not, in and of itself, the covenant of grace. The Mosaic law is a republication of the principle of the covenant of works. The law says, “Do this and live” (Lev 18:5). The gospel (the covenant of grace) says, “Christ has done it; receive it and live.” But although the law is not the gospel, it was given to advance the covenant of grace. It does this by showing us that we cannot be justified by the works of the law and thus driving us to Christ. The law was a temporary guardian, the historical matrix for the incarnation, so that the Seed might be born under it, obey it, endure its curse, and thus fulfill it in our place (Gal 3:13; 4:4; Rom 10:4).
Horton quotes Geerhardus Vos:
As Vos states, “The covenant with Israel served in an emphatic manner to recall the strict demands of the covenant of works … It truly contained the content of the covenant of works. But—and one should certainly note this—it contains this content as made serviceable for a particular period of the covenant of grace.”
Horton then adds his own comment fleshing this out:
Although the Sinaitic covenant is based on law, it is only such in the interests of holding out the promise of the covenant of grace. The ultimate promise of a worldwide family of Abraham in a renewed creation is unconditional in its basis, while the continuing existence of the national theocracy as a type of that everlasting covenant depended on Israel’s obedience. Therefore, the Sinai covenant was an administration of the covenant of grace in that it served to further the interests of that gracious promise.
With that qualification—“in that it served to further the interests of that gracious promise”—the law can be called an administration of the covenant of grace, even though the law, in and of itself, is not the covenant of grace. Kline put it this way: “The Law covenant was a sub-administration of the Covenant of Grace, designed to further the purpose and program of the gospel.”
 Michael S. Horton, “A Covenant Theology Response,” in Covenantal and Dispensational Theologies: Four Views on the Continuity of Scripture, ed. Brent E. Parker and Richard J. Lucas (Downers Grove, IL: IVP Academic, 2022), 197.
 Horton, “Covenant Theology,” in Covenantal and Dispensational Theologies, 38; quoting Calvin’s commentary on Romans (at Rom 10:5).
 Michael G. Brown and Zach Keele, Sacred Bond: Covenant Theology Explored (Grandville, MI: Reformed Fellowship, 2012), 102-4.
 Meredith G. Kline, Kingdom Prologue: Genesis Foundations for a Covenantal Worldview (Eugene, OR: Wipf and Stock, 2006), 321.
 Meredith G. Kline, By Oath Consigned: A Reinterpretation of the Covenant Signs of Circumcision and Baptism (Grand Rapids: Eerdmans, 1968), 23-24.
 Geerhardus Vos, Reformed Dogmatics, Single-Volume Edition, trans. and ed. by Richard B. Gaffin, Jr. (Bellingham, WA: Lexham Press, 2020), 348 (2.130 in the multi-volume edition).
 Horton, “Covenant Theology,” in Covenantal and Dispensational Theologies, 47.
 Meredith G. Kline, God, Heaven and Har Magedon: A Covenantal Tale of Cosmos and Telos (Eugene, OR: Wipf and Stock, 2006), 128.