From the promise to Abraham, the children of Israel entered Canaan under Joshua's leadership and set up a monarchy under Saul and David. Augustine says that these historical narratives in Scripture could be the work of many, many volumes to exposit, but in general we need to understand that the promises and prophecies in the Old Testament are of three kinds:
- Those made to Israel and the Jewish people;
- Those made to Christians and the church;
- Those made to both.
We may have some other kind of allegorical interpretation other than Augustine's, and he's fine with that so long as we do not slight the historical reality of the narrative.