1)
What is "Megilah Afah"?
1.
Rashi citing Targum Yonasan: A scroll flying in the air.
2.
Rashi: It was a scroll of punishments - "v'Chasuv Eleha Kinim va'Hegeh va'Hi" (Yechezkel 2:10).
3.
Radak (3): This is like the Megilah that Yechezkel saw. It was written "Panim v'Achor" (Yechezkel 2:10, i.e. on both sides). Also this Megilah, one side said "Chol ha'Gonev mi'Zeh Kamoha Nikah", and one side said "v'Chol ha'Nishba... Nikah" (3).
4.
Malbim: The previous visions showed that building this Bayis is not the primary Ge'ulah and Binyan. Now Hashem showed the sins that caused Churban ha'Bayis and Yisrael were exiled a second time.