Charles Ellicott Commentary Isaiah 30:25

"And there shall be upon every lofty mountain, and upon every high hill, brooks [and] streams of waters, in the day of the great slaughter, when the towers fall." — Isaiah 30:25 (ASV)

There shall be upon every high mountain ... —The picture of a golden age is continued. The mountains and hills, often so dry and barren, would flow down with rivers of waters, and irrigate the valleys. And this would coincide with the day of a “great slaughter,” perhaps of the enemies of Israel, perhaps also of the people themselves (judgment coming before the blessing), and of the fall of the “towers” in which they had put their trust. (Compare to Isaiah 40:4.) As before, man’s extremity was to be God’s opportunity. Possibly, however, the “towers” are those of the besiegers of the city.