Where did He see this in Beis Yisrael?
Radak: In Beis Kel and Dan ? the calves were there.
What is "Sha'aruriyah"?
Rashi citing Targum Yonasan: It is an expression of change 1 ? they changed their ways. The same applies to "Shamah v'Sha'arurah" (Yirmeyah 5:30).
Radak: It is an expression of ugliness and filth, like "ka'Te'enim ha'Sho'arim", "Sha'aruris Asasah" (Yirmeyah 29:17, 18:13).
Our text of Yonason says they deviated from the Bris made with them not to serve idolatry. (PF)
What Zenus did Efrayim have there?
Radak: The calves, which Yaravam from Shevet Efrayim made, and was Mezanah after them.
Malbim: They were Mezanah with idolatry.
How did Yisrael become Tamei?
Radak: The 10 tribes served [the calves].
Malbim: Since Efrayim, the ruling Shevet, were Mezanah, the other Shevatim became Tamei. The Zenus was in them, and not in the murdered Kohanim!
