I've received a number of emails and a few comments on my previous post in which I cited Peter Leithart. What was the context for that citation?
My reason for posting Leithart's comment was to underscore the true novelty of the Davidic covenant--that is, its international scope.
After God declares his oath to David in 2 Samuel 7, David exclaims, “thou hast shown me a law for humanity” (2 Sam 7:19). The international character of the “law” associated with the Davidic covenant established at Mt. Zion clearly distinguishes it from the nationalistic pre-occupation of the Torah and the covenant made with Israel through Moses at Sinai. Under Moses Israel was to be separated from the nations—isolation was especially encouraged by the purity laws. However, the Davidic Empire under the reigns of David and Solomon included the surrounding nations (2 Sam 8:11-12; 10:19; 12:30; 1 Kgs 4:20-21; 10:15). Moreover, the foreign Queen of Sheba came to hear Solomon’s wisdom and praised the God of Israel (1 Kgs 10:1-13).
 R. P. Gordon, 1-2 Samuel (Sheffield: JSOT, 1984), 77; Paul Stuhlmacher, Reconciliation, Law, & Righteousness: Essays on Biblical Thoelogy (Philadelphia: Fortress Press, 1986), 115. Hartmut Gese, Essays on Biblical Theology (trans., Keith Crim; Minneapolis: Augsburg Publishing House, 1981), 26, 60-92.