How was God dealing with Israel under the Old Testament promises?
God dealt with Israel as His covenant people under all the Old Testament promises, with everything in their prospect. When they rejected it, God did something totally different that the Old Testament knew nothing of: He turned to the Gentiles.
Les explains that God was dealing with His covenant people, Israel, under all the Old Testament promises, and everything was in their prospect. But when they rejected it, God now does something totally different, something the Old Testament knew nothing of. Les says that God then turns to the Gentiles. This is the contrast in view: Israel had the promises and prospect, but upon their rejection, God turns to the Gentiles.