Therefore their inhabitants were of small power, they were dismayed and confounded; they were as the grass of the field, and as the green herb, as the grass on the housetops, and as corn blasted before it be grown up.

And the inhabitants of them, were weak of hand, they trembled and were confounded, they became like the grass of the field, and the green herb on the tops of houses, which withered before it came to maturity.

And their inhabitants were powerless, They were dismayed and put to shame; They were as the growing grass, and as the green herb, As the grass on the housetops, and grain blighted before it be grown up.

Therefore their inhabitants were of small power, they were dismayed and confounded; they were as the grass of the field, and as the green herb, as the grass on the house-tops, and as corn blasted before it is grown up.

And their inhabitants are feeble-handed, They were broken down, and are dried up, They have been the herb of the field, And the greenness of the tender grass, Grass of the roofs, And blasted corn, before it hath risen up!

This is why their townsmen had no power, they were broken and put to shame; they were like the grass of the field and the green plant, like grass on the house-tops.

And whoever may settle in these, they have trembled, with a weak hand, and they have been confounded. They have become like the hay of the field, and like weeds sprouting on the rooftops, which dry up before they reached maturity.

The weakness of the nations exposed to the Assyrian attacks was as much owing to the divine decrees as was the strength of the Assyrians themselves.
The grass on the house tops - Compare the marginal reference. The vegetation on the flat roofs of Oriental houses is the first to spring up and the first to fade away.

Therefore their (r) inhabitants were of small power, they were dismayed and confounded; they were [as] the grass of the field, and [as] the green herb, [as] the grass on the housetops, and [as corn] blasted before it be grown up.
(r) Thus he describes the wicked, who flourish for a time, and later fade and decay like flowers.

Therefore - Because I had armed thee with my commission and strength, and taken away their spirit and courage.