1)
Who are "Kol Bnei Nechar" from whom they separated?
1.
Rashi: They separated also 1 from their Nochri wives, like it says above (Ezra 10:11). Malbim #1 - they separated from them when Ezra ascended, and afterwards stumbled in them again.
2.
Malbim #2: According to the opinion that this was a different episode (refer to 7:72:3:2), only now Ezra separated them from their Nochri wives.
1
Bnei (masculine) implies that they separated also from others. Above (Ezra 10:44), Rashi explained that they expelled the Nochri wives and their wives' children. Perhaps here he guards lest one err to say that "Bnei" is only the children. (PF)
