Exodus 23:29
I will not drive them out before you in one year, lest the land become desolate and the wild animals multiply against you.
Deuteronomy 7:22
He, the God who leads you, will expel the nations little by little. You will not be allowed to destroy them all at once lest the wild animals overrun you.
Joshua 15:63
The men of Judah were unable to conquer the Jebusites living in Jerusalem. The Jebusites live with the people of Judah in Jerusalem to this very day.
Joshua 16:10
The Ephraimites did not conquer the Canaanites living in Gezer. The Canaanites live among the Ephraimites to this very day and do hard labor as their servants.
Joshua 17:12-13
But the men of Manasseh were unable to conquer these cities; the Canaanites managed to remain in those areas.
Judges 3:1-4
These were the nations the Lord permitted to remain so he could use them to test Israel -- he wanted to test all those who had not experienced battle against the Canaanites.