So Joshua came, and all the people of war with him, against them,.... Being encouraged by the Lord, they set out with Joshua at the head of them, to fight the kings and their forces. It is highly probable that these were not the whole body of armed men in the camp of Israel, but a select company Joshua took of them, and who would be able to make quicker marches on this expedition: by the waters of Merom suddenly; the Targum is,"they lay by the waters of Merom;''as they were thoughtless and careless, and not on their guard, Joshua and his forces came to them suddenly, unawares, and they not provided for them: and they fell upon them; at once, which threw them into disorder and confusion.