7. And the reed and the rush shall wither. He mentions the reed and the rush, because they had abundance of them, and employed them for various purposes; or, it may be thought to mean that the marshes will be dried up.
By the mouth of the brooks. Some render it embankments, but it rather means the fountain itself, which seldom is dried up, though torrents or rivers fail. By the mouth, therefore, he means the source of the river which shall be dried up in such a manner that no part of the country can be watered. Though the source of the Nile was at a great distance, yet not without reason did the Prophet threaten that that river, on whose waters the fertility almost of the whole land depended, shall be dried up at its very source; for in that country rain seldom falls, but its place is supplied every year by the Nile. If that river overflow but scantily, it threatens scarcity and famine; and therefore, when the Prophet threatens that it will be dried up, he means that the whole country will be barren. For this reason he says also, that, even at its very mouth, from which the waters spring up, there will be a lack of waters, so that in that place the herbs will be withered.