Genesis is filled with the foreshadowing of later events. In the book of Joshua the Israelites enter the promised land and begin its conquest, and this event was foreshadowed in Genesis 12.
Abram passed through the land to the place at Shechem, to the oak of Morah. At that time the Canaanites were in the land. Then the LORD appeared to Abram and said, “To your offspring I will give this land.” So he built there an altar to the LORD, who had appeared to him. (Gen. 12:6-7)
Three observations: first, the land is currently occupied (“the Canaanites were in the land”); yet, second, the land would eventually belong to Abraham’s offspring (see the promise in v. 7); and third, the future possession of the land by Abraham’s offspring would ultimately be the work of God (“I will give this land”).
If the current occupants of the land were only temporary stewards, then a conflict was inevitable. For the land of Canaan to become the land of Israel, a conquest is in store.