1)
Who is "Am Yehudah"?
1.
Radak: It is people of other cities [of Yehudah] who came to Yerushalayim. Yirmeyah spoke to them and to the residents of Yerushalayim.
2)
Why does it say "Al Kol Am Yehudah"?
1.
Radak: This is like El.
