Joshua 8:13

13. Joshua went that night, etc It is not probable that all were called out from the camp, but the army was composed of those who were more accustomed to war. That it was sufficiently numerous appears from the fact, that five thousand were withdrawn from it for ambuscade. At first thirty-five thousand appear to be enumerated, but it is clear from the context that the number was not so great. I am rather inclined to conjecture that thirty thousand were led out for open fight, and that five thousand were specially set apart for an ambuscade. Joshua hastens to execute the task assigned to him, commencing his march in the morning, and in this haste we see how effectual the promise had proved. Had not the mind of all been freed from fear he never could have found them so prompt to obey.

Apparently, indeed, little prudence is shown in sending so large a body to proceed by hidden paths to a place suitable for ambuscade. For with whatever silence and composure they might proceed, the mere movement of their feet must have caused a considerable noise. Should any one say that there was nobody to meet them, as all the inhabitants of the district had deserted the fields and taken refuge in the city, we will find it mentioned shortly after, that before the Israelites came near to the city their arrival was known by the king of Ai; and this could scarcely have been without scouts. But granting that they met no one in the fields, it was certainly a difficult matter to pass by, to select a suitable place during night for an ambuscade, and to take possession of it without giving some indication of their presence. With regard to the procedure of Joshua, though he might see that the business could be accomplished by a smaller force, he seems to have been compelled by the recent trepidation of the people to be very careful not to engage them in any enterprise of danger. For had only a few of the army been dispatched they would perhaps have declined a part by which they were to be particularly exposed.