1)
What are "Sha'arei Maves"?
1.
Rashi: Gehinom.
2.
Malbim: Nivchei Yam (places where water was gathered).
2)
What is the significance of not seeing Sha'arei Maves and Sha'arei Tzalmaves?
1.
Malbim: Sometimes Resha'im are punished via Nivchei Yam, and sometimes via the depth. When water overpowers in the depth of seas or the Tehom, sulfurous vapors gather, or fire burns there, or water passes over places of lime prepared to flame up. From there come storm winds and earthquakes, and cities and Medinos are destroyed.
