Joshua 6:1

1.Now Jericho was straitly shut up, etc Jericho is said to be shut up, because the gates were not opened: as in time of war cities are guarded with more than usual care. It is added, by way of emphasis, that they were sealed, or locked up, (63) as if it were said that the inhabitants were attentive in watching, so as not to be taken by surprise. Hence, as it could not be taken by stratagem, the only hope of taking it was by open force. This tends to display the goodness of God to the children of Israel, who would have been worn out by a long and difficult siege, had not a substitute been early provided from heaven. Meanwhile there was a danger, lest being forced into a corner, they might be consumed by want and famine, as there was no means of obtaining food and provender in a hostile region. The Lord, therefore, that they might not sit down despondently before one city, assisted them by an extraordinary miracle, and opened up an entrance to them by throwing down the walls, that they might thereafter have the greater confidence in attacking other cities.

We now see the connection between the two first verses, in the one of which it is said, that Jericho was shut up, and the children of Israel thus prevented from approaching it, while in the other God promises that he will take it for them. He makes this promise with the view of preventing them from tormenting themselves with anxious thoughts. In one word, God, by this easy victory at the outset, provides against their giving way to despondency in future. We, at the same time, perceive the stupidity of the inhabitants, who place their walls and gates as obstacles to the divine omnipotence; as if it were more difficult to break up or dissolve a few bars and beams than to dry up the Jordan.