Why does it mention Yakov and Yisrael?
Malbim: Yisrael refers to the great people.
Yirmeyah was in Egypt. Does he promise Yisraelim there that they will be saved and return? Above (Perakim 43-44), he said that they will be eradicated!
Rashi: Here it refers to Tzadikim who were exiled to Egypt Bal Korcham (against their will).
Malbim (28): Indeed, Nebuchadnetzar eradicated all the Jews in Egypt. This promise is for Jews spread amidst nations other than Egypt.
This was said above (30:10-11). Why was it repeated?
Radak: It discusses here the punishment of the nations against Yisrael. Yisrael, do not fear. You are not like them! Even though [Egypt] will return to their land after their exile, they will not be serene; in the end, they will cease to be a nation, and their name will not be mentioned. Yisrael's name will not cease. Their mention will endure like the days of Shamayim on the land.
