'Behind' in the Bible

You shall do [the same] to Ai and its king as you did to Jericho and its king; [except that] you shall take only its spoil and its cattle as plunder for yourselves. Set up an ambush for the city behind it [on the west side].”

He commanded them, saying, “Listen closely, you are going to lie in wait and ambush the city from behind it. Do not go very far away from the city, but all of you be ready.

So they stationed the people, all the army—the main encampment that was north of the city, and their rear guard on the west side of the city—and Joshua spent that night in the valley.

Now when the king [and the people] of Ai saw it, the men of the city hurried and got up early and went out to meet Israel in battle, the king and all his people at the appointed [time and] place before the desert plain (the Arabah). But he did not know that there was an ambush against him [waiting] behind the city [on the west side].