the hill country, the foothills, the Arabah, the slopes, the wilderness, and the Negev — the lands of the Hittites, Amorites, Canaanites, Perizzites, Hivites, and Jebusites):
These conquests cover hill country, foothills, Arabah, slopes, wilderness, and Negev, along with the lands of the Hittites, Amorites, Canaanites, Perizzites, Hivites, and Jebusites.
It broadens the introduction by naming the regions and peoples included in the inheritance.
7And these are the kings of the land that Joshua and the Israelites conquered beyond the Jordan to the west, from Baal-gad in the Valley of Lebanon to Mount Halak, which rises toward Seir (according to the allotments to the tribes of Israel, Joshua gave them as an inheritance 8the hill country, the foothills, the Arabah, the slopes, the wilderness, and the Negev — the lands of the Hittites, Amorites, Canaanites, Perizzites, Hivites, and Jebusites): 9the king of Jericho, one; 10the king of Jerusalem, one; 11the king of Jarmuth, one; 12the king of Eglon, one; 13the king of Debir, one; 14the king of Hormah, one; 15the king of Libnah, one; 16the king of Makkedah, one; 17the king of Tappuah, one; 18the king of Aphek, one; 19the king of Madon, one; 20the king of Shimron-meron, one; 21the king of Taanach, one; 22the king of Kedesh, one; 23the king of Dor in Naphath-dor, one; 24and the king of Tirzah, one.