Did Eilam carry an Ashpah?
Radak: The people of Eilam carried them.
Malbim: Eilam shot arrows.
What is "Ashpah"?
Rashi: It is a quiver that holds arrows.
What is "b'Rechev Adam Parashim"?
Radak citing Targum Yonasan: In the chariot of a man, and with him a pair of cavalry.
Malbim: There were so many quivers that they needed to carry them in chariots and horses carrying men.
What is the meaning of "v'Kir Erah Magen"?
Rashi citing Targum Yonasan: They stuck their shields on the wall. This is like "Aros Al Ye'or" (19:7), "u'Mis'areh k'Ezrach Ra'anan" (Tehilim 37:35) [Radak - and 'Me'ureh b'Tarafshe' - Chulin 46a]. They stuck their shields on the wall to dig underneath it 1 , to topple it.
Rashi: Kir is the name of a city [Radak - of Melech Ashur], like "va'Yagleha Kirah" (Melachim II, 16:9). People of that state revealed their shields [Radak - to come for war] against Yerushalayim. Radak - Erah is revealing, like "Es Mekorah He'erah" (Vayikra 20:18)
Malbim: The verse depicts that [Bnei] Kir hold shields and protect from archers' arrows, like generals' youths hold shields in front of them - "v'Nosei ha'Tzinah Holech Lefanav" (Shmuel I, 17:7).
Kli Paz citing Mahari: I.e. the shields protect them from what people on top of the wall shoot, throw or drop on them.