What does Genesis 15:21 mean?
The Lord continues to define the area His chosen people will possess, by naming more of the people groups which currently occupy it. This is in the context of God's vow to grant all the land between the Wadi el-Arish—the "river of Egypt"—and the Euphrates to Abram's descendants. This final verse lists the Amorites, who were already mentioned as the future recipients of God's judgment, as well as the Canaanites, the Girgashites, and the Jebusites.Genesis 15:1–21 falls between Abram's heroic rescue of Lot in Genesis 14 and his less-than-heroic choice to have a child with his wife's servant in chapter 16. Chapter 15 features Abram's hard questions to the Lord about how the lofty promises of uncountable descendants and possession of the land will be kept. God responds, in part, by formalizing His covenant promises to Abram with an elaborate ritual. He also reveals to Abram details about the difficult circumstances his descendants will face before they come back to take possession of the land ''in the fourth generation.''
Genesis 15 consists entirely of a long encounter between the Lord and Abram. When the ''word of the Lord'' comes to Abram in a vision to bring reassurance of God's support for him, Abram takes the opportunity to press God with questions. Abram asks both about his childlessness and how he can know he will one day possess the land of Canaan. God responds, and Abram believes. God's response includes leading Abram through a covenant ritual involving slaughtered animals, as well as a prophecy about the future of Abram's descendants before the time will come to occupy the Promised Land.
