What is the meaning of "Kol Ma'avar Mateh Musadah"?
Rashi: All passages of the strength of his multitudes - all the places where Ashur passed and destroyed - on the day of Ashur's fall, Hashem will let them hear of his downfall, and they will rejoice with drums and harps.
Radak: Wherever Hashem will pass in the camp, the staff that Hashem prepared to place it on Melech Ashur
What is the meaning of "Asher Yani'ach Hashem Alav"?
Malbim: Hashem will put His Gevurah on this strong Shevet.
Why does it say "b'Supim uv'Chinoros"?
Radak: Hashem will not strike Ashur with weapons. Rather, it is as if the angel plays drums and harps while striking them, for "b'Avod Resha'im Rinah" (Mishlei 11:10).
Malbim: This is at a time when all places in Yehudah were rejoicing with instruments over Chag ha'Pesach.
Why does it say "uvi'Milchamos Tenufah Nilcham Bah"?
Rashi: The verse should be re-arranged - with drums and harps, every place where they passed, Hashem will fight an offensive war against them.
Rashi citing a Midrash: The Tenufah (waving) of Ketzir ha'Omer stood for Yisrael in that war. It was the night of the 16th of Nisan 1 .
Radak: This is like a repeat of "b'Supim uv'Chinoros", for one who plays instruments waves his hand.
Malbim: Initially, when they sang only the song of the Chag in Yerushalayim, Hashem did not fight Ashur. He merely scared them with His voice. Now, when the Simchah of the Korban spread through all streets of Yerushalayim - they sing Hallel wherever it is eaten - Hashem increased His war against Ashur.
We reap the Omer that night, and offer it during the day.
Why is it written Bah, but we pronounce it Bam?
Radak: Bah refers to the Machaneh. It can be feminine - "ha'Machaneh ha'Achas" (Bereishis 32:9). Bam refers to the people in the camp.
