Matthew Poole and continuators on Joshua 8:14

14 And it came to pass when the king of Ai saw it, that they hasted, and rose up early, and the men of the city went out against Israel to battel, he, and all his people , at a time appointed , before the plain , but he wist not that there were liers in ambush against him , behind the city.

To wit, all his men of war, for the rest were left in Ai, v. 16.

At a certain hour agreed upon between the King and People of Ai, and of Bethel too, who were their Confederates in this Enterprize, as it may seem from v. 16. Possibly they might appoint the same hour of the day on which they had fought against Israel with such good success, looking upon it as a lucky hour.

i. e. Towards or in sight of that plain or valley in which the Israelites were, that so they might put themselves in Battel-array.

The former success having made him more careless and secure, as is usual in such Cases, God also blinding his mind, and infatuating him, as he useth to do with those which he intends to destroy.