What is the meaning of "Hich'is Efrayim Tamrurim"?
Rashi: Efrayim angered his Creator bitterly, via disgracing His Nevi'im and betraying Him. Radak #2 - Tamrurim is like Merorim.
Radak #1: They angered Hashem with the Mizbechos that they built, which were like Galim (12) and markers. This is like "Simi Lach Tamrurim" (Yirmeyah 31:20).
What do we learn from "v'Damav Alav Yitosh"?
Rashi: Hashem considers that Efrayim spilled the blood of Yisrael via causing them to cling to idolatry. One who causes another to sin is worse than one who kills him. We learn from Amon and Mo'av. They caused Yisrael to cling to Ba'al Pe'or 1 , and the Torah punishes them more than Egypt and Edom, who drowned Yisrael in the river and came to greet them with the sword [respectively - Sifri Re'eh 252].
Radak: Innocent blood that Efrayim spilled, Hashem will spread on him. "Yitosh" is spreading, like "Netushim Al Pnei Kol ha'Aretz" (Shmuel I, 30:16), "va'Yitosh Al ha'Machaneh" (Bamidbar 11:31).
Malbim: Efrayim killed its kings, e.g. Beis Yaravam and Beis Achav and other kings, for serving idolatry. Afterwards, those who killed them returned to serve Ba'alim and the calves! This shows that they murdered them without reason. The verse depicts that the murdered king spreads his spilled blood on the nation that killed him.
This is like the opinion that hiring Bil'am applies also to Amon. Refer to Devarim 23:5:151:3 and the notes there. (PF)
What is "Cherpaso"?
Rashi: Efrayim reviled Shlomo - "va'Yarem Yad ba'Melech" (Melachim I, 11:26). He rebuked him in public for building the Milo, like it says in Sanhedrin 101b.
Radak: Efrayim reviled Hashem via the calves.
Malbim: When Efrayim killed their kings, they reviled them for serving idolatry - this shame is returned to them.
Why does it say "Yashiv Lo Adonav"?
Rashi: Hashem will punish [Yaravam], for he did worse than [Shlomo, whom he rebuked].
Radak: Hashem will pay Efrayim on his head for spilling innocent blood and reviling Him via the calves. Even though he does not recognize His mastery, Bal Korcho (against his will) He is his Master!
Malbim: Refer to 12:15:2:3.
