John Wesley on Joshua 8:14

His people - Namely, all his men of war, for the rest were left in Ai, ver.16. At a time appointed - 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 ver.17. Possibly they might appoint the same hour of the day on which they had fought against Israel with good success, looking upon it as a lucky hour. Before the plain - That is, towards or in sight of that plain or valley in which the Israelites were, that so they might put themselves in battle - array. Against him - The former success having made him secure, as is usual in such cases; God also blinding his mind, and infatuating him, as he useth to do with those whom he intends to destroy.