Whose blood and flesh is Hashem referring to?
Rashi: He is referring to the blood and flesh of the enemy. 1
Riva (39, citing R"M of Kutzi): You (the enemy) said that I drink (Yayin Nesicham). I do not drink, but I will 'intoxicate' my arrows (satiate them) in (an abundance of) your blood! You said that I eat (Chelev Zevachemo). I do not eat, but My sword will consume [your] flesh!
Whose slain and captives is Hashem referring to?
Rashi: He is referring to the slain and the captives of Yisrael that the enemy killed and captured.
What is the meaning of "me'Rosh Par'os Oyev"?
Targum Onkelos: It means that Hashem will remove the crowns from the heads of the enemy.
Da'as Zekenim, Hadar Zekenim (41): I will pay (punish) the head of the enemy.