What are "ha'Rishonos"?
Rashi: It is what I promised to Avraham about Galus Mitzrayim - "v'Gam Es ha'Goy [
What came?
Rashi: My first promises.
Radak: The first Nevu'os about Sancheriv came in the days of Yeshayah.
What are "Chadashos"?
Rashi: They are new promises to My nation, about the second Galus.
Radak: New Nevu'os that you did not hear. I will inform you before they sprout. You will know that just like the first ones were fulfilled, the latter will be fulfilled, i.e. taking Yisrael out of this Galus.
Malbim: One who predicts the future will be believed only in one of two ways. (a) He was already tested - he predicted the future and it was fulfilled. (b) The matter that he predicts, part of it already began, and he says what will be in the end 1 . My first predictions already were fulfilled. Therefore, I need not predict matters that already began. I can say totally new matters!
If he has not been tested, why will people believe that the end will be like he says? (PF)
Why does it say "Titzmachnah"?
Radak: This is a metaphor, like "Atzmi'ach Keren l'David" (Tehilim 132:17), "Atzmi'ach Keren l'Veis Yisrael" (Yirmeyah 29:21). The new matter will be like new vegetation that appears on the land after it was hidden. So will be the salvation of Yisrael.
