You counted the houses of Jerusalem and tore them down to strengthen the wall.
10. And you numbered the houses of Jerusalem. He means that the city was closely examined on all sides, that there might not be a house or building which was not defended. Others think that the houses were numbered, that they might have a supply of watchmen.
What is meant by the covering of Judah, which in the beginning of this paragraph is said to be discovered, is not agreed. The fenced cities of Judah were a covering to the country; but these, being taken by the army of the Assyrians, ceased to be a shelter, so that the whole country lay exposed to be plundered.
Commenting on Isaiah 22:8-14
And ye have numbered the houses of Jerusalem,.... To know what number of men were in them, and how many could be spared to do duty, either as watchmen or soldiers; or to know how to levy the tax, and what money they would be able to raise, to defray the charge of the defence of the city; or to see what provisions they had...