What is "l'Cheilah"?
Rashi: Its walls. This is like "Cheil v'Chomah" (Eichah 2:8). Radak, Rashi there - Cheil is a small wall around a big wall.
Why does it say "Shisu Libchem l'Cheilah"?
Malbim: See Who is the wall surrounding the city that did not let the storm enter (i.e. Hashem)!
What is the meaning of "Pisgu Armenoseha"?
Rashi: Lift its buildings. This is like "Ashdos ha'Pisgah" (Devarim 3:17); the Targum is Ramasa.
Radak: See its buildings, which are high. They are seen, like a peak.
Malbim: Ascend to the peak of the castles, and see Who is the Guard on top of the castles to guard them - "Elokim b'Armenoseha Noda l'Misgav" (verse 4)!
What will you tell to the last generation?
Rashi: Its height and beauty. Radak - each generation will tell to the next, until the last generation.
Malbim: Tell Who guards the city and the castles.
