1)
Why does it say "Bas Bavel"?
1.
Bamidbar Rabah (7:10): Edom is called Bas Bavel, for just like Bavel destroyed the Mikdash and exiled Yisrael, so did Edom.
2.
Radak: Now it returns to discuss Bavel.
2)
Why does it say "Shedudah"?
1.
Radak: It will be pillaged.
2.
Malbim: Koresh already pillaged Bavel.
3)
Who will repay them?
1.
Radak: Daryavesh ha'Midi, who destroyed Bavel.
2.
Malbim (8-9): Hashem already started to pay Bavel (Koresh pillaged them). Aside from the Churban, they will be paid for what they bestowed to Yisrael amidst hatred, they will be paid with hatred and vengeance. Koresh will come again and totally destroy them.
