1)
Why do they gird sackcloth?
1.
Malbim: It is to mourn over their evil deeds.
2)
Why are they covered with trembling?
1.
Malbim: It is due to the punishments.
3)
Why are there shame on their faces, and bald patches on their heads?
1.
Malbim: The shame is due to their sins. The bald patches are due to mourning over the punishments.