7. Therefore—because of the devastation of the land.
abundance—literally, "that which is over and above" the necessaries of life.
brook of … willows—The fugitives flee from Nimrim, where the waters have failed, to places better watered. Margin has "valley of Arabians"; that is, to the valley on the boundary between them and Arabia-Petræa; now Wady-el Arabah. "Arabia" means a "desert."