Why does it say "Ki Anochi cha'Shachal"?
Radak: How can Melech Ashur save you, even if he will want to? I am like a lion to you ? "no one can save from Me!"
Malbim: This is not a natural illness that can heal, and one is saved from it. I strike you like a Shachal (old lion) and Kefir (young lion). Kefir does not leave its den to tear prey. It sits in its den waiting to ambush what comes close. Shachal goes out to tear prey and bring to its cubs. I will be a Shachal to Efrayim; I will leave My abode to tear there. I will be a Kefir to Yehudah ? I dwell there. This is like it said, I will be like Ash to Efrayim and Rekev to Yehudah (12).
Why is "Ani" repeated?
Radak: This is to strengthen the matter. The same applies to "Re'u Atah Ki Ani Ani Hu" (Devarim 32:39).
Malbim: Their troubles are not natural or chance, rather, Hashgachah. This is both in Efrayim, where I will tear and go (bring the prey to elsewhere, like a Shachal), and in Yehudah.
What will Hashem carry?
Rashi: He will carry what He tore.
Malbim: In Yehudah, I will tear and hold [the prey; I will not take it elsewhere].
