Why does it say "El Chomas Bavel"?
Radak: This is like Al. There are many verses like this in this Sefer.
What is the significance of raising a flag?
Radak: When you conquer it, raise a flag on the walls to show that it is yours. This is the custom, when they conquer a city they put flags on the towers and walls.
Malbim: It is to fight the wall.
What is "ha'Mishmar"?
Metzudas David: It is the siege on the city.
When should they strengthen the Mishmar?
Radak: Before the city is captured. Malbim - it is to prevent Giborim from falling on the camp from the wall.
What is the purpose of the guards?
Malbim: They are around the wall, lest people flee.
What is the purpose of the ambush?
Malbim: It is to cut off those who flee and hide.
Why does it say "Gam Zamam Hashem"?
Rashi: Hashem intended so for a long time. It says "Gam" here due to the latter "Gam"; verses speak like this. Radak - each includes the other. This is like "Gam Atem Gam Malkechem" (Shmuel I, 12:25).
Why does it say "Gam Asah"?
Rashi: He fulfilled His intent.
