This Book of the Law shall not depart from your mouth, but you shall meditate in it day and night, that you may observe to do according to all that is written in it. For then you will make your way prosperous, and then you will have good success.

So Joshua arose, and all the people of war, to go up against Ai; and Joshua chose thirty thousand mighty men of valor and sent them away by night.

Joshua therefore sent them out; and they went to lie in ambush, and stayed between Bethel and Ai, on the west side of Ai; but Joshua lodged that night among the people.

And when they had set the people, all the army that was on the north of the city, and its rear guard on the west of the city, Joshua went that night into the midst of the valley.

Joshua therefore came upon them suddenly, having marched all night from Gilgal.