What is the meaning of "v'Od Bah Asiriyah"?
Rashi: Also the remainder, I will repeatedly refine it and eradicate people, until will remain only absolute Tzadikim who return to Me with all their hearts. Malbim - this was in the generation of Chizkiyah.
Radak: Asiriyah is a noun; its grammatical form is like Tachteha. Ten more kings will rule in the land after this Nevu'ah, which was in the year that Uziyah died. The 10 are Yosam, Achaz, Chizkiyah, Menasheh, Amnon, Yoshiyah, Yo'achaz, Yehoyachin, Yehoyakim and Tzidkiyah.
Radak citing Targum Yonasan: One out of 10 will remain. Malbim - i.e. Shevet Yehudah.
What is the meaning of "v'Shavah v'Haysah Leva'er"?
Radak: After [the 10 kings - refer to 6:13:1:2], the land will revert to be consumed - everything will be finished. All will be exiled, and Yerushalayim will be destroyed. This is like "u'Vi'arta ha'Ra" (Devarim 13:6), "Ka'asher Yeva'er ha'Galal" (Melachim I, 14:10).
Why does it specify "ka'Elah vecha'Alon" (elm and oak)?
Rashi #1: When they shed their leaves, in winter, they repeatedly shed (Malbim - they have many leaves), until remains only the Matzeves (trunk and branches) - also they, the Zera Kodesh found in the land remaining in their Kedushah, will be a Matzeves. Malbim - so the Resha'im, who are the shells and leaves, will wither, and the Matzeves will remain. This answers "until when" (11) - until they are like elm and oak, and only the Matzeves remains; they will hear the words of Nevu'ah.
Rashi #2: "Sha'ar Shaleches" was in Yerushalayim (Radak - the Beis ha'Mikdash - Divrei ha'Yamim I, 26:16), like it says in Ezra; there were elm and oak planted there.
Radak: Their eradication will be like elm and oak. In winter, they shed all their leaves, and they appear dry.
What is "Matzavtah"?
Rashi #1: Refer to 6:13:1:1.
Rashi #2: Its planting 1 . Therefore I do not totally eradicate them - I planted Kodesh seed.
Radak: Their standing. Their moisture remains in them, even though they appear dry. In Nisan, they return to sprout leaves. So "Zera Kodesh" - even though all of them will be exiled, do not think that they will be finished off in Galus and not return to their land.
Radak: The Targum of "va'Yita" (Bereishis 21:33) is u'Netziva. The suffix Hei refers to the land, like it says "v'Shavah v'Haysah Leva'er."