Radak: The prefix Vov does not add to what precedes this. It is a new matter - because you did such and such, He will do to you such and such. Also "va'Yisa Avraham Es Einav" (Bereishis 22:4, is a new matter) and many verses are similar. Because you rejoice over those who fight Malchus Beis David, you will fall to harsher [rulers], i.e. Machaneh Ashur.

Malbim: Because you did not want the spring, Hashem will bring the river against you.

Radak: When the river overpowers (overflows its banks), it washes away everything that it passes over. So Melech Ashur and his great camp conquered all of Yehudah, except for Yerushalayim.

Malbim: Kings of Malchus Ashur were anointed by the Pras river, to show a flooding, strong kingship. "Atzumim" is in quality, and Rabim in quantity.

Radak: It is his great army, via which he became honored over all nations, and conquered them.

Rashi: The river water will overpower to rise over all its sources. Radak - even though the sources are deep, it says Alah (will rise), for Eretz Yisrael is higher than all lands. The entire land will fill with [Machaneh Ashur], just like the sources are full of water.

Malbim: Sometimes a river overflows its banks when they seal Afikav, i.e. the conduits through which its water flows. This river, even though it flows through Afikav, even so it will overflow its banks. The Nimshal is, even though Melech Ashur will fight many nations, to which he sent troops, still his camp is so great that it fills Eretz Yehudah - "v'Chalaf bi'Yhudah" (8).

Rashi: The river overflows Gedosav, i.e. Gedudav, i.e. its erect banks, in a place where the river flows between its erect banks. It is as if it is in a gutter pipe.

Radak: "Gedosav" are the banks of the valley above; they are higher than the valley. These are a metaphor for all fortified cities of Yehudah.

Malbim: Refer to 8:7:4:2.