Judges 3:5
And the children of Israel dwelt among the Canaanites, Hittites, and Amorites, and Perizzites, and Hivites, and Jebusites: And the children of Israel dwelt among the Canaanites, Hittites, and Amorites, and Perizzites, and Hivites, and Jebusites:
After the division of the land Israel had not taken full possession but dwelt among the peoples allowed to remain in portions of its inheritance in the land of promise, namely the Canaanites, Hittites, Amorites, Perizzites, Hivites, and Jebusites. This was the introduction to the period in which the Israelites lived among the Canaanite tribes they permitted to remain where they had not possessed all the land. Those peoples were left in portions of Israel's inheritance so that the younger generation that had not fought in Joshua's time would be tested, and driving them out would develop essential traits of character.
The nations God had not driven out became snares and traps, scourges and thorns to Israel, threatening its continued possession of the land. Living among them exposed Israel to its neighbors' practices and gods, and the awful moral surroundings exerted a demoralizing influence. Instead of driving them out, the younger Israelites learned their ways and joined with them, and close association led to intermarriage and serving their gods, so that the blending of family ties produced a mixed religion that was no longer the pure truth God had given.
This dwelling among them helps account for Israel's perversity and unbelief, and belongs to the repeated pattern of backsliding from God followed by suffering, oppression, captivity and servitude, then returning to God followed by forgiveness and deliverance, which reveals the long-suffering and goodness of God. Israel's relations with the surrounding peoples stand as a warning about marriage, illustrating the danger addressed by other scriptures that counsel against marriage outside the faith. Their failure warns that later generations may abandon the work begun by those before them rather than carry it forward.