Joshua 8:4

And he commanded them, saying
At the time he sent them away;

behold, ye shall lie in wait against the city, [even] behind the city;
that is, on the west side of it, ( Joshua 8:9 ) ;

go not very far from the city, but be ye all ready;
to enter into it, as soon as the forces are drawn out eastward to meet the army of Israel.