Why will He not have mercy any more?
Radak: This is if they do not improve their deeds.
Why does it say "b'Yad Re'ehu uv'Yad Malko"?
Radak: They will destroy them. Also their king will destroy them ? both a Melech Yisrael, and a Melech Nochri who rules over them.
Malbim: Amidst Sin'as Chinam among them, one will stab his friend. Kings of Bayis Sheni killed the nation and eradicated them.
What is the meaning of "Mamtzi"?
Radak: He summonses. This is like "v'Es ha'Olah Himtzi'u Elav li'Nsacheha" (Vayikra 9:13).
What do we learn from "v'Chitesu Es ha'Aretz"?
Radak: Between both of them (commoners and kings), they will destroy Eretz Yisrael.
Malbim: Due to the different Kitos (factions), and the cruel kings, they were cut, separated and perished.
Why will Hashem not save from them?
Radak: Because they sinned against Me.