Contradiction with Exodus 23:31
Whereas Genesis 15:19 lists subdued nations, Exodus 23:31 states God will establish borders of the land, hinting at larger territorial promises not specified in Genesis 15:19.
Exodus 23:31: And I will set thy bounds from the Red sea even unto the sea of the Philistines, and from the desert unto the river: for I will deliver the inhabitants of the land into your hand; and thou shalt drive them out before thee.
Contradiction with Judges 2:21-23
This passage implies God left some nations to test Israel, which seems to contradict the idea in Genesis 15:19 of fully giving the lands to Abram's descendants.
Judges 2:21-23: I also will not henceforth drive out any from before them of the nations which Joshua left when he died:
Contradiction with Deuteronomy 20:16-18
Commands to utterly destroy other nations seem to contrast with the mixed coexistence of nations mentioned in Genesis 15:19.
Deuteronomy 20:16-18: But of the cities of these people, which the LORD thy God doth give thee [for] an inheritance, thou shalt save alive nothing that breatheth:
Contradiction with Joshua 13:1-7
God lists remaining land in Canaan yet to be conquered, differing from the complete inheritance suggested in Genesis 15:19.
Joshua 13:1-7: Now Joshua was old [and] stricken in years; and the LORD said unto him, Thou art old [and] stricken in years, and there remaineth yet very much land to be possessed. [to...: Heb. to possess it]
Paradox #1
The contradiction in Genesis 15:19 could be related to the mention of specific groups, such as the Kenites, that some historians believe did not exist until a later time period than when the events of Genesis are traditionally dated. This can lead to debates about the accuracy of the historical timeline in the text.