John Calvin Commentary Joshua 7:2

"And Joshua sent men from Jericho to Ai, which is beside Beth-aven, on the east side of Beth-el, and spake unto them, saying, Go up and spy out the land. And the men went up and spied out Ai." — Joshua 7:2 (ASV)

And Joshua sent men from Jericho, etc. To examine the site of the city and reconnoiter all its approaches was an act of prudence, so that they might not, by hurrying on at random through unknown places, fall into an ambush. But when it would be necessary shortly after to advance with all the forces, to send forward a small band with the intention of taking the city seems to betray a lack of military skill.

Hence, it would not have been strange that two or three thousand men, in a sudden attack, were panic-struck and turned their backs. And it was certainly expedient for the whole army that twenty or thirty thousand should have spread in all directions as foraging parties. We may add that even the act of slaying, though no resistance was offered, was in itself sufficient to wear out a small body of troops.

Therefore, when the three thousand or so were repulsed, it was only a just recompense for their confidence and sloth. The Holy Spirit, however, declares that their small numbers were not the cause of the defeat and ought not to bear the blame for it. The true cause was the secret counsel of God, who intended to show a sign of his anger but allowed the number to be small so that the loss might be less serious.

And it was certainly a rare display of mercy to chastise the people gently and without any great defeat, with the intention of arousing them to seek an immediate remedy for the evil. Perhaps, too, the inhabitants of Ai would not have dared to attack the Israelites if they had advanced against the city in full force. The Lord therefore opened a way for his judgment, and yet modified it so as only to detect the hidden crime, under which the people might otherwise have been consumed as by a lingering disease.

But although there is nothing surprising in the defeat of the Israelites, who fought on disadvantageous terms on lower ground, it was, however, perfectly obvious that they were defeated by fear and the failure of their courage before they came to close quarters; for by turning their backs, they gave up the higher ground and retired to the slope of a valley. The enemy, on the other hand, showed how thoroughly they despised them by the confidence and boldness with which they ventured to pursue the fugitives at full speed in the direction of their camp. In the camp itself, such was the trepidation that all hearts melted.

I admit, indeed, that there was cause for fear when, after having gained so many victories as it were in sport, they saw themselves so disgracefully defeated. In unaccustomed circumstances, we are more easily disturbed. But it was a terror from heaven that dismayed them more than the death of thirty men and the flight of three thousand.