Joshua 8:7

Then ye shall rise up from the ambush
When they should see a signal made, that in ( Joshua 8:18 Joshua 8:19 ) ; and when their watch, they might set in a proper place, should see Israel flee, and the men of Ai at a distance from their city, pursuing, and give notice of it to the ambush:

and seize upon the city;
enter into it, and take possession of it, its fortresses, and secure its passes:

for the Lord your God will deliver it into your hand;
Joshua expresses himself with great confidence, having the promise of God, and relying on it.