What Does Genesis 15:13 Mean?

Then the Lord said to him: "Know for certain that for four hundred years your descendants will be strangers in a country not their own and that they will be enslaved and mistreated there." The content of the divine word in the darkness is not what Abram might have hoped for: four hundred years of slavery and mistreatment in a foreign land before the land possession is fulfilled. The covenant promise is confirmed in chapter 15, but the timeline of its fulfillment includes four centuries of displacement. The promise is real; the path to its fulfillment includes sustained suffering.

The four hundred years figure (cf. four generations in verse 16, numbers that the New Testament and Exodus account interpret variously) places the land possession in a future that extends well beyond Abram's lifetime, beyond his children's and grandchildren's lifetimes, into a period that only his distant descendants will experience. The covenant patriarch is being invited to receive a promise that he will not see fulfilled, not in any of its major dimensions. That reception, by faith, of a promise for others at cost to oneself is the fullest expression of the faith that verse 6 has already declared as righteousness.

The prediction of the Egyptian sojourn and slavery is the background against which the Exodus will be read as covenant fulfillment. When Moses confronts Pharaoh, he does so as the agent of a God who told Abram this would happen and promised to judge the nation responsible and bring out His people with great possessions. The Exodus is Genesis 15:13-14 happening on schedule. Jesus spoke of His death as similarly predicted and on schedule: "The Son of Man goes as it has been decreed." The covenant fulfills itself through what looks like delays and disasters to those inside the timeline.