the land ... rise up wholly as a flood - The land will, as it were, be wholly turned into a flooding river (a flood being the image of overwhelming calamity, Dan 9:26).
cast out and drowned, etc. - swept away and overwhelmed, as the land adjoining the Nile is by it, when flooding (Amo 9:5). The Nile rises generally twenty feet. The waters then “cast out” mire and dirt (Isa 57:20).