1)
Who are Tzarei Yehudah and Binyamin?
1.
Rashi: They are Nochrim that Sancheriv settled in Eretz Yisrael - "va'Yavo Melech Ashur mi'Bavel umi'Kusah ume'Avah ume'Chamas u'Sfarvim va'Yoshev b'Arei Shomeron Tachas Bnei Yisrael."


