What Does Genesis 15:21 Mean?

The Amorites who appear in this final verse of the chapter's land list are the same people whose sin "has not yet reached its full measure" in verse 16. The covenant that promises the land names the people whose continued presence delays the promise, and then lists that same people among those whose land will eventually be given. The Amorites are simultaneously the reason for the delay and the people through whom the delay will be resolved when their iniquity finally ripens. The internal logic of the covenant's timeline is complete: wait for the iniquity to fill; then receive the land.

The Girgashites and Jebusites round out the list's ten peoples. The Girgashites appear rarely in the Old Testament outside these lists; their precise identity and location within Canaan are not fully established by the available historical or archaeological record. The Jebusites are the most specifically located: they inhabited the city of Jebus, which became Jerusalem, and they maintained control of that city until David captured it in 2 Samuel 5. The Jebusite presence in the covenant-boundary list thus connects the Abrahamic covenant directly to the Davidic city that will become the covenant's central location.

The chapter that began with "Do not be afraid" ends with a comprehensive naming of the obstacles and occupants that stand between the covenant promise and its fulfillment. The fear that was addressed in verse 1 was real; the obstacles named in verses 19-21 are real; the promise that bridges between them is the most formal and legally binding covenant that the Old Testament records between God and a human. The smoking firepot between the pieces has made the promise as certain as anything that exists in the universe, because the one who passed through the pieces is the maker of everything that exists. Jesus is the seed of Abram through whom the Gentile peoples come into this covenant's inheritance, which is why Paul wrote, "If you belong to Christ, then you are Abraham's seed, and heirs according to the promise."