Why does it mention the seven Kena'ani nations regarding Yericho?
Rashi, from Bamidbar Rabah 15:15: Yericho was on the border of Eretz Yisrael. It was the bolt and lock. All seven 1 nations gathered in it [to fight Yisrael].
We do not find that Ba'alei Yericho fought Yisrael. It was closed against Yisrael (6:1)!
Radak: Perhaps leaders of the city went to the kings of Kena'ani to warn them about Yisrael, and meanwhile Yericho was captured, and these leaders were with the kings who gathered afterwards to fight Yisrael (9:1,2). 1
Malbim: Ba'alei Yericho refers to the kings who gathered afterwards (9:1) to avenge Yericho. There it [lists the six other nations, but] does not list Girgashi, and here it includes Girgashi! Initially Girgashi gathered, but afterwards they feared and fled 2 .
Radak: The Midrash (refer to 24:11:1:1) says that all seven nations gathered in Yericho to fight Yisrael. If they actually fought, why did the Navi not record this?!
Yerushalmi (Shevi'is 6:1) implies that the Girgashi fled upon receiving Yehoshua's letters, offering the Kena'anim to make peace, flee or fight! However, one can say that they fled only later. (PF)
How can the verse say "I gave [all seven] into your hands"? We never fought the Girgashi!
Malbim: Some (the other six) I gave into your hands, and some (Girgashi) I sent away (refer to 24:12:1:2).