The Monoethnic Nature of the Mosaic Covenant

One of the “problems” with the covenant that God made with Israel at Sinai (i.e., the old covenant) is its monoethnicity. We need to be clear about this: the Sinaitic and Deuteronomic covenants were made with one nation, the nation of Israel.

The monoethnic nature of the Sinaitic covenant can be seen in the following verses in particular:

“Now therefore, if you will indeed obey my voice and keep my covenant, you shall be my treasured possession among all peoples, for all the earth is mine, but you shall be to me a kingdom of priests and a holy nation” (Exod 19:5–6);

“You shall be holy to me; for I, Yahweh, am holy, and have separated you from the peoples, that you should be mine” (Lev 20:26).

The Deuteronomic covenant, being an expanded renewal of the Sinaitic covenant, was also exclusively made with Israel:

“For what great nation is there that has a god so near to it as Yahweh our God is to us, whenever we call upon him? And what great nation is there that has statutes and rules so righteous as all this law that I set before you today?” (Deut 4:7–8);

“For you are a people holy to Yahweh your God. Yahweh your God has chosen you out of all the peoples on the face of the earth to be his people, his treasured possession” (Deut 7:6);

“you are a people holy to Yahweh your God. Out of all the peoples on the face of the earth, Yahweh has chosen you to be his treasured possession” (Deut 14:2);

These are the terms of the covenant Yahweh commanded Moses to make with the Israelites in Moab, in addition to the covenant he had made with them at Horeb. Moses summoned all the Israelites and said to them: “... You shall keep the terms of this covenant, and do them, so that you may prosper in everything you do. All of you are standing today before Yahweh your God—your leaders and chief men, your elders and officials, and all the other men of Israel, together with your children and your wives, and the foreigners living in your camps who chop your wood and carry your water—in order to enter into the covenant of Yahweh your God and his oath, to confirm you this day as his people, that he may be your God as he promised you and as he swore to your fathers, Abraham, Isaac and Jacob; and it is not with you alone that I am making this covenant and this oath, but with those who are standing here with us today before Yahweh our God, and also with those who are not here with you today” (Deut 29:1–2, 9–15).

Understanding the ethnic particularity of the Mosaic covenant helps us to understand the need in God’s plan of salvation for a new covenant. The Mosaic covenant is “problematic” from the perspective that God’s plan involved bringing blessing to the nations as part of a covenant relationship (Gen 12:3). This is something that the Apostle Paul came to realize. Comparing the monoethnic nature of the Mosaic covenant to the Abrahamic promise in Gen 12:3 led Paul to understand that there had to be, in the purposes of God, a new covenant which would open up the door of righteousness and salvation to the Gentiles, and which would fulfill, subsume, and thereby supercede, the Sinaitic and Deuteronomic covenants that God had made previously with Israel.

Thus Paul contrasted the Abrahamic promise with the Mosaic covenant:

The law [of Moses], introduced 430 years later, does not set aside the covenant previously established by God and thus do away with the promise. For if the inheritance depends on the law, then it no longer depends on the promise; but God in his grace gave it to Abraham through a promise (Gal 3:17–18).

Paul also understood that it was through Jesus Christ, as proclaimed in the Christian gospel, that the Abrahamic promise of blessing to the nations had been realized:

Scripture foresaw that God would justify the Gentiles by faith, and announced the gospel in advance to Abraham: “All nations will be blessed through you” (Gal 3:8);

So in Christ Jesus you are all children of God through faith, for all of you who were baptized into Christ have clothed yourselves with Christ. There is neither Jew nor Gentile, neither slave nor free, nor is there male and female, for you are all one in Christ Jesus. If you belong to Christ, then you are Abraham’s seed, and heirs according to the promise (Gal 3:26–29).

Or as Paul has written in Eph 2:11–16, 19, concerning how the dividing wall of the law of Moses was “destroyed” through the death of Christ on the cross, thereby allowing Gentiles to be members of God’s covenant people:

Therefore, remember that formerly you who are Gentiles by birth and called “uncircumcised” by those who call themselves “the circumcision”—which is done in the body by human hands—that at that time you were separate from Christ, excluded from citizenship in Israel and foreigners to the covenants of the promise, without hope and without God in the world. But now in Christ Jesus you who once were far away have been brought near by the blood of Christ. For he himself is our peace, who has made the two groups one and has destroyed the barrier, the dividing wall of hostility, by setting aside in his flesh the law [of Moses] with its commands and regulations. His purpose was to create in himself one new humanity out of the two, thus making peace, and in one body to reconcile both of them to God through the cross, by which he put to death their hostility … Consequently, you are no longer foreigners and strangers, but fellow citizens with God’s people and also members of his household.

Being limited to one nation, the Mosaic covenant cannot by definition bring salvation to the nations. Only one covenant can: the multiethnic, new covenant in Christ Jesus.

The Covenantal Logic and Meaning of Paul’s Argument in Romans 4:15–17a

In Rom 4:13–17a, Paul gives a succinct explanation as to why the promise of the blessing of life must ultimately come through faith rather than through the Mosaic faith of obedience to torah. This further strengthens his argument in Rom 4:1–12 that the example of Abraham proves that the blessing of justification comes through faith rather than through the works of the law of Moses. The fact that Abraham was right with God even before he was circumcised proves that justification is not limited solely to bona fide members of the Mosaic covenant, contrary to what Paul’s non-Christian Jewish opponents and the Christian Judaizers were advocating; but this needed further explication.

Therefore, in Rom 4:13, Paul considers the issue of how the promise that God made with Abraham (for him and all of his spiritual descendants to inherit the world) would be realized. The promise was not “through the law … but through the righteousness of faith” (Rom 4:13). It is very important to realize that the word law in Rom 4:13 refers specifically to the law of Moses. The word law in Rom 4:13 is not law in general, but specifically the law over which Paul and his Jewish opponents were arguing, i.e., the law of Moses. We need to recognize at this point that the divine promise of blessing given to Abraham in Gen 12:2–3 is grammatically, and therefore logically, dependent on the command of Gen 12:1 (see “The Inheritance of Eternal Life through Faith instead of Law in Romans 4:13” for a more detailed explanation of this). But the law of command given to Abraham in Gen 12:1 is not law in the sense of being Mosaic law. As Paul points out in Gal 3:17, the law of Moses did not arrive on the scene until 430 years afterwards. In other words, the promise of the blessing of life that God graciously made with Abraham was not subject to the Mosaic covenant when it was first made. Even though this promise would effectively come under the regulation of the Mosaic covenant after Sinai, the promise was larger than the law of Moses. The Abrahamic covenant was not a subset of the Mosaic covenant; rather, the Mosaic covenant was a subset of the Abrahamic.

The significance of the promise being realized through the righteousness of faith for Abraham in the beginning is that, if the giving of the law some 430 years later were to change that original condition, then God would have shown himself to be inconsistent and unfaithful to his word. If the giving of the Mosaic law changed the original condition regarding the realization of the promise, then this would be to render faith useless, and the covenant of promise itself would end up being annulled (Rom 4:14). Implied in Paul’s argument in Rom 4:14 is that God would not do such a thing as this. Having entered into an agreement with Abraham concerning how Abraham and his descendants would be blessed, God could not rightly change this commitment midstream.

This then prompted the question (particularly to Paul’s Jewish opponents) concerning why the Mosaic covenant was given in the first place. If the Mosaic covenant is not the ultimate regulator of the realization of the promise, then why was the Mosaic covenant made in the first place? Why save Israel out of Egypt to place the nation under the law? Paul answers this question very succinctly in Rom 4:15: “For the law produces wrath; but where there is no law, neither is there transgression.” What Paul is really saying here is that the primary function of the law in old covenant Israel was to bring about God’s wrath against the people. This is not to say that obedience to the law was not the way of life for the small minority of Israelites who had the law written in their hearts during the old covenant age. Paul is speaking in Rom 4:15 in terms of the broad sweep of salvation history during the old covenant age. Romans 4:15 is not an abstract theological statement, but a statement explaining the function of covenant failure in salvation history. The law of Moses, far from being the solution (as Paul’s Jewish opponents were advocating), was part of the problem. The main purpose in God giving Israel the law was so that God’s anger would be revealed against sinful Israel, i.e., that Israel would be rendered guilty before God, without excuse (Rom 3:19–20).

In Rom 4:16 Paul explains the deeper purpose behind the primarily negative purpose in God giving the law. He identifies two main reasons. Firstly, the law was given to Israel so that God’s dealing with humanity might be “according to grace.” If Israel had kept covenant with God, and received blessing as a result, that would still be the work of God; but Israel initially failing, only to be restored later on, makes for a better story in the sense that the gracious side of God’s character has an opportunity to be revealed. It is almost as if God, wanting to prove his greatness and humanity’s total dependence on him, has deliberately set things up for humanity in Adam, and Israel in Moses, to fail, “in order that every mouth might be stopped, and the whole world come under the judgment of God” (Rom 3:19–20), in order that his gracious response might be seen and appreciated. Simply put, the fact that the promise of eternal life ultimately comes through faith in Jesus rather than through submission to the Mosaic covenant serves to highlight God’s grace. Secondly, justification by faith also means that salvation is not just limited to Israel, but every believer (regardless of ethnic origin) can participate in the promise. Didn’t God say in Gen 17:5 that Abraham would be “the father of many nations” (Rom 4:17)? In fact, that is the meaning of the name Abraham! “No longer shall your name be called Abram, but your name shall be Abraham, for I have made you the father of a multitude of nations” (Gen 17:5).

Paul’s Jewish opponents found it hard to accept, but Paul argues strongly in Rom 4 for the primacy of the new covenant in Christ over against the old covenant in Moses. That, in the salvation historical purposes of God, the Mosaic covenant would be superseded by a new covenant in Christ Jesus serves to highlight God’s grace and to open up salvation to the Gentiles in fulfillment of God’s promise of Gen 12:3.

The Identity and Theology of Paul's Jewish Opponents

In my previous posts entitled “The Apostle Paul’s Understanding of the Old Testament View of the Law” and “The Apostle Paul’s Understanding of the Old Testament View of the Gospel” I have presented some thoughts regarding the first aspect of the Jewish context of the theology of the Apostle Paul, namely, the theological context of the Hebrew Scriptures (i.e., the Old Testament) in which the Apostle Paul operated. The second aspect of Paul’s Jewish context is the identity of his Jewish opponents.

Here are some quotes from my essay “Paul and the New Covenant Paradigm” in the book An Everlasting Covenant: Biblical and Theological Essays in Honour of William J. Dumbrell from the sub-section that discusses the identity of Paul’s Jewish opponents:

“Paul’s Jewish opponents in general were not ignorant of the Old Testament doctrines of grace, sin, or faith. Their key characteristic was that they were fierce advocates of Mosaic covenant theology. They believed that this system of theology (which was based on the Old Testament) was still normative. Paul, however, no longer viewed Mosaic covenant theology as normative in the way that it had been previously. Since his encounter with Christ on the road to Damascus, he had come to view Mosaic covenant theology in effect as old covenant theology (2 Cor 3:6-14). That is to say, the system of Mosaic covenant theology, which had been valid during the old covenant age, had now been rendered obsolete through the coming of Christ and the establishment of the new covenant, a situation that had been foreshadowed in the Mosaic law itself. Paul’s Jewish opponents had more or less correctly understood the way that things were under the old covenant, but they had failed to see how the old covenant would be surpassed or exceeded (2 Cor 3:9-10) by the new covenant in Christ. The fundamental issue for Paul, therefore, was upholding, in the face of opposition from the advocates of traditional Mosaic covenant theology, God’s new covenant arrangement in Messiah Jesus” (p. 133).

“The non-Christian Jews of Paul’s day rejected Jesus and the Christian gospel primarily in the name of faithfulness to Moses and traditional Jewish teaching (see John 5:16, 18; 7:14-24, 45-52; 9:16; 16:2; Acts 22:3; Rom 10:2), while the Christian Judaizers sought to change the universal Christian gospel (which offered salvation to Gentiles on equal footing with Jews) into a Jewish gospel, where conversion to Judaism and keeping the law of Moses were viewed as being necessary for salvation (Acts 15:1, 5). In this way, the Judaizers were attempting to make Christianity fit snugly into the framework of the Mosaic covenant” (p. 133).

In other words, I agree here with William Dumbrell’s assessment of the Antiochene Judaizers as being Jews who “probably endeavoured to fit Jesus into the Sinai compact, which they saw as continuing … By their demand for the imposition of the Mosaic Law on Christian converts, they were in fact making demands for Christian incorporation into the Mosaic and Sinaitic structure” (William J. Dumbrell, Galatians: A New Covenant Commentary [Blackwood: New Covenant, 2006], 38–39).

“The dispute between Paul and his Jewish opponents, therefore, fundamentally revolved around the proper interpretation of the Mosaic covenant in God’s plan of salvation. At stake between Paul and his Jewish opponents was the proper interpretation of the Old Testament” (Coxhead, “Paul and the New Covenant Paradigm,” 134).

In general, Paul’s Jewish opponents were advocates of orthodox Mosaic covenant theology, which defined righteousness in terms of obedience (i.e., commitment or faithfulness) to the Mosaic covenant and its stipulations (i.e., the law of Moses) in accordance with the teaching of Deut 6:25. The Jewish nature of the theology of Paul’s Jewish opponents needs to be understood correctly before we can truly understand the significance of the Christian doctrine of justification by faith apart from the works of the law, which Paul strongly defended in his epistles to the Galatians and Romans.

The Jewish Context of the Theology of the Apostle Paul

In section one of my essay “Paul and the New Covenant Paradigm” in the book An Everlasting Covenant: Biblical and Theological Essays in Honour of William J. Dumbrell I look at the Jewish context of Paul’s theology in Galatians and Romans.

The Jewish context of Paul’s theology is very important for understanding the nature of the problem that Paul was addressing in Galatians and Romans, but overall this dimension is something that has frequently been mishandled or overlooked in the history of the interpretation of these epistles.

“The Jewish context of Paul’s theology has two main aspects: firstly, the theological context of the Old Testament; and secondly, the nature of the Jewish opposition that Paul had to face during his ministry” (p. 121).

“When it comes to the theological context in which Paul operated, the most important element is the Hebrew Scriptures (i.e., the Old Testament) and the theological ideas communicated therein. There are two important aspects to the Old Testament that impact upon Paul’s theology: the Old Testament view of the law, and the Old Testament view of the gospel” (p. 121).

“The second aspect of Paul’s Jewish context is the identity of Paul’s Jewish opponents” (p. 130).

In my next post I will provide some quotes from the sub-section that deals with the Old Testament view of the law.

The Paradox of Faith and Law: Is the Law of Faith or Not?

There are some who, following Gal 3:12, say that the law was not of faith. I can say that too, but the question is what do we all mean when we say that. Some scholars understand the idea that the law is not of faith to mean that the Mosaic covenant was a covenant that operated on the basis of works, which determined solely the temporal blessing of Israel in the land; eternal blessing was to be found in the Abrahamic covenant, and was to be inherited by faith alone. There are yet other scholars who take the Mosaic covenant to be a covenant of works that demanded perfect obedience from Israel, which means that Israel inevitably could not keep the covenant with God.

I agree that the language of obedience and doing dominates in the section of the Pentateuch that deals with the Mosaic covenants (i.e., Exod 19–Deut 34). I think that we must say that the Mosaic covenant demanded the works of the law (Deut 6:25; Ezek 18:5-9; Rom 10:5; Gal 3:12). But it is not as if the language of faith is not employed at all in relation to the Mosaic covenants in the Old Testament. A classic case in point is the author of Ps 119 calling obedience to the Mosaic law the way of faith (Ps 119:30). He also identifies the law of Moses as the object of his faith: “I believe in your commandments” (Ps 119:66).

The key to sorting out this issue, I believe, lies in understanding that faith was typically viewed in a holistic way by Moses and the prophets. The consequence of this is that, under the Mosaic covenants, faith and obedience end up being co-relative concepts. Paying attention to Old Testament anthropology, in particular the role of the heart as the integrating center of the human psyche, is important for understanding why a holistic concept of faith was employed by Moses and the prophets.

So, the law is not of faith, but in another sense it is. It is interesting that when Jesus forcefully critiqued the scribes and Pharisees in Matt 23, he accused them of hypocrisy for being particular about the law of tithing but neglecting the weightier matters of the law: “Woe to you, scribes and Pharisees, hypocrites! For you tithe mint and dill and cumin, and have neglected the weightier matters of the law: justice and mercy and faith. These you ought to have done, without neglecting the others” (Matt 23:23).

It is significant that Jesus views faith/faithfulness as being one of the important ethical truths prescribed by the law. It is also important to note in this regard that Jesus’ language does not allow the law to be bifurcated, enabling us to single out faith as operating on a level of its own, separate from the law or the commandments. Faith is spoken of here by Jesus on a par with justice and mercy as the human response required as Israel’s covenant obligation—the parallels with Mic 6:8 are intriguing. And faith, along with justice and mercy, and tithing, are equally (according to Jesus’ teaching in this verse) what the law commanded Israel to do. Jesus clearly says that faith is one of the weightier matters of the law that Israel was to do: “these it is necessary to do, while not leaving aside those.” In other words, Jesus is saying that faith was commanded as part of the law of Moses.

The law is not of faith, but … it is!

The paradox of continuity and discontinuity strikes again.

Justification by the Works of the Law in Pauline Perspective

A number of times commentators on this blog have raised the question of how Paul’s negative view of works of the law fits in with my suggestion that a legitimate doctrine of justification by the works of the law existed as part of the Mosaic covenant.

Upon the established of the covenant at Sinai, the Abrahamic promise regarding blessing for Israel was channeled through the Mosaic covenant. In this way, Israel’s response to the Mosaic covenant would not only be her response to the word of God as revealed through Moses, but would also constitute her response to the promises given to Abraham, Isaac, and Jacob.

As Israel responded positively to the Mosaic covenant, she would be judged by God as acting rightly under the terms of the covenant. Acting rightly for Israel was faith, an acceptance of the word of God; but because the word of God revealed to Israel dealt with all sorts of things, Israel’s faith was by definition holistic in nature. Hence, the typical Mosaic description of Israel’s covenant obligation as being that of obeying God’s voice and keeping his covenant (Exod 19:5). Furthermore, as Israel responded rightly, God's judgment that she had been acting rightly would result in her being declared righteous under the terms of the covenant (Deut 6:25). In other words, a legitimate doctrine of justification by the works of the law applied to Israel under the Mosaic covenant. Being adjudged by God to be covenantally righteous on the basis of this holistic faith (i.e., through a positive response to the law of Moses), all the blessings of the covenant, including the forgiveness of sins, would follow as a consequence of God’s promise of blessing to the righteous.

The idea that there was a legitimate doctrine of justification by the works of the law during the old covenant age obviously contradicts the common Protestant interpretation of Paul which says that no one (apart from Christ) can ever be justified by the works of the law. But this common understanding of Paul is the result of reading Paul in isolation from the theology of the Old Testament, for the Old Testament teaches that justification by the works of the law was a reality during the old covenant age. Contrary to the common Protestant assumption that no one (apart from Christ) can keep the law or keep covenant with God, the Old Testament teaches that the law could be kept, and that it was indeed kept by some Israelites. This is evident in the Old Testament teaching that a righteous minority in Israel had the law written on their hearts (Ps 37:31; 119:11, 69), and in the claim of a number of godly Israelites that they had kept covenant with God (Ps 44:17-18; 119:56). Those Israelites who had the law of Moses written on their heart and who consequently kept covenant with God were the faithful remnant. By God’s grace, David was an example of such a person (1 Kgs 14:8; Ps 18:20-24). That the law could be kept, and was kept by a faithful minority in Israel, is due to the fact that the Mosaic covenant was a gracious covenant. Keeping the law was not a matter of absolute perfection, but being committed to the covenant in the context of grace.

Now if a doctrine of justification by the works of the law applied to old covenant Israel, how did they go? Ever since the establishment of the Sinaitic covenant, the Old Testament has been interested in this issue. So how did Israel go in her covenant relationship with God? Terribly is the answer. But it is not as if all were as equally as bad as each other. To be precise, the Old Testament teaches that the faithful minority kept covenant with God, but the disobedient majority broke covenant with God. And here is the important point: because the majority of Israel broke covenant with God, the curses of the covenant came down upon the nation as a whole (see Ps 44:4-22). In other words, even though the faithful remnant were covenantally righteous, the blessings that God had promised to the righteous could not be realized for them in full under the Mosaic covenant. Even after the return of the Jews from exile in Babylon, sin was still a problem in Israel. Thus, the Old Testament record of the constant problem of covenant disobedience in Israel leads to the conclusion that the Mosaic covenant was not able to bring in righteousness and the fullness of blessing for the nation. Justification by the works of the law was not able to bring the fullness of justification or blessing to Israel, let alone to all the families of the earth, the other nations being excluded from membership in the Mosaic covenant by definition.

This impotency of the Mosaic covenant to achieve full justification and blessing led the Old Testament prophets to look forward to a new covenant, which would be characterized by a more powerful work of God in the hearts of his people (Deut 30:6; Jer 31:33; Ezek 36:26), which would move them to covenant obedience (Deut 30:14; Ezek 36:27), in order that the promised blessings might finally be realized (Deut 30:1-10; Ezek 36:28-30). The failure of the Mosaic covenant also led the faithful remnant to place their hope in the righteousness of God that would be revealed in the future (Ps 98:1-3; Isa 51:4-6; 59:15b-20), when God would act to bring in the fullness of salvation and the realization of all that he had promised. This righteousness of God would be revealed in the sight of the nations (Ps 98:2), and torah observance, and hence covenant righteousness, would be opened up to the nations as a result (Isa 2:1-4; 42:1-4; 49:6).

Hence Paul’s reading of the Old Testament is correct: justification by the works of the law was not and is not able to bring the fullness of justification and the blessing of Abraham to all flesh. This would only be achieved through the eschatological revelation of the righteousness of God apart from the law of Moses (Rom 3:21) in the person and work of the Messiah, to which all people (regardless of nationality; Rom 3:29-30) can respond positively, by faith in the Messiah and his message, the gospel (Rom 3:22). Hence the new covenant doctrine of justification by faith in Christ (Rom 3:28), and Paul’s polemic that it was a wrong for the orthodox Jews and Christian Judaizers of his day to think that adherence to the Mosaic covenant could solve the problem of human sin.

Mosaic Covenant or Covenants?

One of the keys to understanding the bigger picture of the Bible is understanding the concept of covenant. And in order to understand the biblical concept of covenant, you really need to understand the nature and function of the Mosaic covenant, or should I say Mosaic covenants? For when we look at the biblical record, there are three covenant ceremonies associated with Moses.

The first one is the Sinaitic covenant, whose inauguration ceremony is recorded in Exod 24. The inauguration ceremony of the Sinatic covenant in Exod 24 is considered in Jewish tradition to be the marriage ceremony between God and Israel.

The sin of the golden calf was viewed by God (and Moses) as a breaking of the Sinaitic covenant (Exod 32:7-8, 19, 21, 25, 30-31), so serious that it put the whole covenant relationship between God and Israel under threat of virtual annulment (see Exod 32:9-10). It was only through the intercession of Moses that God relented from destroying the people (Exod 32:11-14), and only through the intercession of Moses again that God withdrew his intention not to accompany the people into the promised land (see Exod 33:1-3, 12-17). This commitment of God to go up with his people implied the re-establishment of the Sinaitic covenant, and this is recorded in Exod 34:10-33. This re-establishment is symbolized in the rewriting of the Ten Commandments on the replacement stone tablets (Exod 34:1, 4, 27-28). Nevertheless, the fact that Moses could no longer speak with God face to face (Exod 33:20-23), and that there was no delegation from the people invited to celebrate before the Lord à la Exod 24:9-11 (compare with Exod 34:3, 28) suggests that, despite the re-establishment of the covenant, the intimacy of the relationship between God and Israel had been "irrevocably" affected in a negative way through Israel's bovine rebellion. The veiling of Moses' face, which commences in Exod 34:33-35, seems to emerge as a consequence of Israel's rebellion, and presumably was also a symbol of the impaired state of the relationship.

The third covenant ceremony involves the Deuteronomic covenant. This covenant was a renewal and updating of the Sinaitic covenant appropriate for when Israel crossed the Jordan to take up her inheritance in the promised land. This was shortly to take place, and the whole of the book of Deuteronomy is basically a series of four sermons through which Moses is concerned to spell out to the people of Israel the nature of God's covenant relationship with them and their covenantal obligations in the light of this relationship. The inauguration ceremony of the Deuteronomic covenant is not narrated explicitly, but appears implicitly in Deut 29:1–32:47.

I think most of us tend to think about the Mosaic covenant in the singular. But it is interesting that Deut 29:1 distinguishes between the covenant made at Horeb (i.e., Sinai) and the Deuteronomic covenant made in the land of Moab. So should we speak of the Mosaic covenants (in the plural) rather than the Mosaic covenant (in the singular)?

My view is that both expressions are valid. Speaking more precisely, there are two covenants and one covenant renewal associated with Moses in the Pentateuch. So speaking of the Mosaic covenants is most precise. But the covenant renewal in Exod 34 is effectively a renewal of the first Sinaitic covenant, not a new covenant per se. And the Deuteronomic covenant is really just an updated and expanded renewal of the Sinaitic covenant. God only has one covenant relationship with Israel, so it is also appropriate to speak of the Mosaic covenant. Plus there is scriptural precedent for grouping a plurality of related covenants together under the singular term covenant. An example of this is found in the reference to the covenant made with the fathers in Jer 31:32. This verse refers back to the Exodus and hence the Sinaitic covenant, but "the covenant" in question obviously also includes the Deuteronomic covenant within its scope, as this later covenant was the major body of legislation that functioned to regulate Israel's life in the promised land.

By the way, a similar problem exists in relation to the Abrahamic covenant. Compare Gen 15:9-21 with Gen 17:1-14.