What is putting Panav against him, and why will He do so?
Rashi: If he will not heed the Navi's words, I will put My anger against him. Radak ? Targum Yonasan says so; this is like "u'Faneha Lo Hayu Lah Od" (Shmuel I, 1:18), "Achaperah Fanav" (Bereishis 32:21).
Radak: He will turn from all His affairs and engage in this.
Malbim: I will turn My Hashgachah to punish him and destroy him.
What is "va'Hasimmosihu"?
Rashi citing Targum Yonasan: I will eradicate him.
What is "l'Os veli'Mshalim"?
Radak: From the great evil that I will bring on him, he will be a sign and Mashal. This is like "Tesimenu Mashal ba'Goyim" (Tehilim 44:15).
Malbim: In this generation he himself will be an Os (sign). They will see the plagues on him; he will be a sign to rebels. After death he will be a Mashal ? they will compare, like what happened to this Rasha will occur to other Resha'im.
Why does it add "v'Hichrativ mi'Toch Ami"?
Malbim: In future generations I will cut him off. His name and memory of him will be lost.