יהושע, פרק י״ז, פסוק י״ג

The process of settling the land was complex. Even when the Israelites gained the upper hand, they did not always finish removing the previous inhabitants. It took time for the Israelites to grow strong enough to impose taxes on the local population [ביאור שטיינזלץ]. Yet, although they eventually gained the power to fully subjugate the Canaanites, they failed to actually expel them [מצודת ציון]. As a direct result of avoiding this complete expulsion, the Canaanites remained living within the territory of the tribe of Manasseh for many generations [ביאור שטיינזלץ].