Perhaps the most significant is the mention of the Philistines, since this is the first time that the Philistines are mentioned in Joshua. They were a mixed group of people who settled in Canaan in large numbers around 1200 BC. They remained formidable opponents until David’s reign (Judges 14:1; 1 Samuel 31:1–13; 2 Samuel 5:17–25). Because they developed iron before the Israelites they also had a cultural and military advantage (1 Samuel 13:19–22).1
In addition, the reference to Sidon is also of interest. Sidon was far to the north and thus God’s promise to drive out the people living in that region was meant to be an encouragement to Israel that obedience to God will result in their territory being greatly expanded.2
2 This is the land that yet remains: all the regions of the Philistines, and all those of the Geshurites