What is the meaning of "[Parash Ma'aleh] v'Lahav Cherev]"?
Rashi: It is the sword's blade - "va'Yavo Gam ha'Nitzav Achar ha'Lahav" (Shoftim 3:22).
Radak: The horseman raises the sword's blade. The prefix Vov in v'Lahav is extra, like "va'Yisa Avraham Es Einav" (Bereishis 22:4).
Malbim: The cavalry will go high on the mountains where chariots and horses 1 cannot go.
Parash is a soldier on a horse! Perhaps the horse will go partially up the mountain, and the soldier will ascend higher than the horse can. (PF)
What is "Lahav"?
What is "Berak Chanis"?
Rashi: A polished, shiny spear. A flash comes out of it.
Why does it say "v'Rov Chalal"?
Radak: The cavalry will kill many.
What do we learn from "v'Choved Pager"?
Rashi: They increase Pegarim (dead bodies). Radak - the matter is repeated in different words. Kaved is many, like "Amecha ha'Kaved ha'Zeh" (Melachim I, 3:9). A body is called Peger only when it is dead.
Malbim: They will sweep the bodies, like they sweep waste-heaps.
What is the meaning of "v'Ein Ketzeh la'Geviyah"?
Rashi: There is no count of the dead bodies cast in it.
Malbim: Even though they will sweep the bodies, they cannot remove all of them.
Why does it say "v'Chashlu bi'Gviyasam"?
Rashi: There were so many dead bodies that passersby stumbled on them.
Radak: The enemy will stumble on the dead bodies.