1)
What is this "cup of wine of anger"?
1.
Rashi: It is a Nevu'ah of punishments.
2.
Malbim: It is a metaphor. There will be among them great rebellions and tumult.
2)
Why do both Yayin and Chemah have the prefix Hei?
1.
Radak: The word Samuch [to Chemah] is omitted. It should say ha'Yayin Yayin ha'Chemah. This is like "ha'Am ha'Milchamah" (Yehoshua 8:11), "ha'Sefer ha'Miknah" (below, 32:12) and similar verses.
3)
What is the significance of drinking the cup?
1.
Rashi: Prophesize for them that they will not return at all.