Joshua did not draw back the hand that held his battle lance until he had devoted to destruction all who lived in Ai.
26. For Joshua drew not his hand back, etc As by raising the spear he gave sign and pledge of hope as it were from heaven, he did not cease to keep the minds of his followers fixed upon it until they were masters of the city.
We have here an account of the improvement which the Israelites made of their victory over Ai. 1. They put all to the sword, not only in the field, but in the city, man, woman, and child, none of them remained, Jos 8:24.
Commenting on Joshua 8:23-29
For Joshua drew not his hand back wherewith he stretched out his spear,.... But continued it, and that stretched out: until he had utterly destroyed all the inhabitants of Ai; just as the hand of Moses was held up, and kept held up until Amalek was discomfited by Joshua, Exo 17:12.