Judges 3:27
And it came to pass, when he was come, that he blew a trumpet in the mountain of Ephraim, and the children of Israel went down with him from the mount, and he before them. And it came to pass, when he was come, that he blew a trumpet in the mountain of Ephraim, and the children of Israel went down with him from the mount, and he before them.
The Canaanites were left remaining in the land after Joshua's time for the testing of those Israelites who had been too young to take part in the fighting under Joshua. Their continued presence was appointed as the means by which that younger generation would be proved. By striving to drive them out, those who had known no war would gain personal experience in conflict and conquest. This trumpet call in the mountain of Ephraim belongs to the record of the deeds of the leaders God raised up as saviors when Israel had fallen into captivity in times of national crisis.