Witsius: The Decalogue Reflects The Dual Character Of the Mosaic Covenant

XIV. The law, which God in this manner published, consists of ten words or commandments, Exod. 34:28, Deut. 4:13. Wherefore the Greeks also called it δεκάλογος, the decalogue. Moreover the contents of those ten words are various.

1st, There is the prescription of certain duties; and in this, the nature of a law, as such, properly consists.

2dly, The threatening of divine vengeance against the transgressors thereof, as in the second and third commandments; and this is the sanction of the covenant of works, from which all threatenings are derived, as we explained at large, book iii. chap. i sect. 22.

3dly, The proposal of divine grace and favour; and as this is made to sinners, and that under a condition, not of perfect, but of sincere obedience, so far it flows from the covenant of grace.

Herman Witsius, The Economy of the Covenants, 2.175

    Post authored by:

  • R. Scott Clark
    Author Image

    R.Scott Clark is the President of the Heidelberg Reformation Association, the author and editor of, and contributor to several books and the author of many articles. He has taught church history and historical theology since 1997 at Westminster Seminary California. He has also taught at Wheaton College, Reformed Theological Seminary, and Concordia University. He has hosted the Heidelblog since 2007.

    More by R. Scott Clark ›

Subscribe to the Heidelblog today!


  1. Although it happened almost half a century ago, I remember it like it happened yesterday. I had recently discovered that Christ is God, and that He had died because of my sins! I was burdened and guilt ridden, and troubled by what I should do in light of this awful realization. Then a friend invited me to her church where the pastor preached on the imputation of Christ’s active and passive righteousness. It blew my mind and it blew me away! I am most pleased to say that I have never recovered. It was simply the most beautiful, comforting, assurance of God’s love. What an outrageous scandal, “God justifies the wicked!” Rom. 4: 5

    In Christ, God’s very own righteousness is mine! So I am fully justified, even though I am a sinner who deserves only eternal damnation under God’s law, but because Christ obeyed perfectly and died to pay the penalty I deserve, I am as acceptable to God as His own dear Son, under the covenant of grace! How then, as adopted sons, can we not sincerely strive to obey our loving Father’s law, not under threat of death or punishment, but in the desire to please Him and love Him with all our heart. I had stumbled across the third use of the law, where our imperfect obedience is accepted by the Father, not for our justification, but because we are already perfectly justified, by grace alone, through faith alone, in Christ alone: A fact that will be only be vindicated on the last day!

  2. Dr. Clark,

    What is the dual nature of the old covenant, and where is that idea expressed in the quote from Witsius?

  3. I think the article on Witsius 2014, that is linked above, is key to understanding the dual nature of the Mosaic covenant. It sets Mount Sinai in contrast to Mount Zion, or the sweetness of the covenant of grace against the severity of covenant of works.

    Having ratified the new covenant of grace with Abraham, God, at Sinai, shows them their sin and misery in the strictness of the law, by republishing the law in minute detail, and even an animal cannot touch the holy mountain without being instantly killed, so they should understand that only God can fulfill it, as He promised to do in the Abrahamic covenant by ratifying the new covenant of grace first revealed in the garden, when God alone walked through the pieces.

    In the types and shadows of the Mosaic sacrifices, God appoints priests to administer the covenant of grace, giving glimpses into the manner in which God himself would fulfill the covenant of works, where the priests, alter, and victim represent the ultimate Sacrifice promised in the Abrahamic covenant.

    The republication of the law in the Mosaic covenant is not, do this and live, but rather, because I have taken upon myself the severity and penalty of the law, in gratitude and love, believe my promises and live to willingly obey as my adopted children who obey their Father out of love. God says, in the prologue to the ten commandments because I delivered you from slavery, out of the land of Egypt….Egypt being typological of bondage to the law as a covenant of works, but now the law is a way of expressing love and gratitude in the new covenant of grace. Tenure in the land should have been through
    believing the promises of the covenant of grace, and obeying God out of love and gratitude. But just as happens in the church today, only a remnant believed and the rest, in their unbelief, still sought to be justified, at least in part, by their own performance of the law. So God judged them under the covenant of works, because they had rejected the promises of the covenant of grace by trying to be accepted by God through their works.

    The Mosaic covenant was as republication of the covenant of works, as Witsius explains, as a contrast to the sweetness of the covenant of grace. John Owen also makes this point in great detail. It was not to tell the Israelites to do this in order to live, but in love and gratitude for the gift of salvation and adoption as my sons, obey me because you believe these promises, freely in love and gratitude, because I, the Lord you God, do all that the law requires, in perfect detail, so that your imperfect obedience of love is accepted as fruit and evidence of your faith and love, for Me.

    • Sinclair Ferguson has some very helpful lectures on Owen, on the Internet to which I am very indebted, for this insight into the dual nature of the Mosaic covenant.

Comments are closed.