Contradiction with Genesis 13:15
Promises land to Abram and his seed "forever," contradicting the conquest and division of the land in Joshua 12:8.
Genesis 13:15: For all the land which thou seest, to thee will I give it, and to thy seed for ever.
Contradiction with Exodus 23:31
Describes the promised land with different borders than those mentioned in Joshua 12:8.
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 Numbers 33:53
Instructs Israelites to dispossess the inhabitants of the land, while Joshua 12:8 summarizes the conquered lands.
Numbers 33:53: And ye shall dispossess [the inhabitants] of the land, and dwell therein: for I have given you the land to possess it.
Contradiction with Deuteronomy 11:24
Provides different territorial boundaries for Israel than those conquered and listed in Joshua 12:8.
Deuteronomy 11:24: Every place whereon the soles of your feet shall tread shall be yours: from the wilderness and Lebanon, from the river, the river Euphrates, even unto the uttermost sea shall your coast be.
Contradiction with Judges 1:19
Mentions that Judah could not drive out the inhabitants of the valley, in contrast to the complete conquest described in Joshua 12:8.
Judges 1:19: And the LORD was with Judah; and he drave out [the inhabitants of] the mountain; but could not drive out the inhabitants of the valley, because they had chariots of iron. [drave...: or, possessed the mountain]
Contradiction with Judges 2:21-22
States that God did not drive out all the nations quickly, unlike the comprehensive list of conquests in Joshua 12:8.
Judges 2:21-22: I also will not henceforth drive out any from before them of the nations which Joshua left when he died: