John Gill Commentary Psalms 78:55

"He drove out the nations also before them, And allotted them for an inheritance by line, And made the tribes of Israel to dwell in their tents." — Psalms 78:55 (ASV)

He cast out the Heathen also before them
The seven nations, the Hittites, Girgashites, Amorites, Canaanites, Perizzites, Hivites, and Jebusites, (Deuteronomy 7:1)

and divided them an inheritance by line :
the land of Canaan was divided among the nine tribes and a half by Joshua, the other two and a half having had their portion assigned them on the other side; this distribution was made very exactly by lot, by line, and measure, so that every tribe had their proper portion and inheritance; see (Joshua 13:6–8Joshua 13:32) (14:1-5) ,

and made the tribes of Israel to dwell in their tents ;
in the cities, towns, villages, and houses of the Heathen cast out before them.