Adam Clarke on Deuteronomy 32:42

From the beginning of revenges - The word פרעות paroth, rendered revenges, a sense in which it never appears to be taken, has rendered this place very perplexed and obscure. Mr. Parkhurst has rendered the whole passage thus: -

I will make my arrows drunk with blood;

And my sword shall devour flesh,

With the blood of the slain and captive

From the hairy head of the enemy.

Probably מראש פרעות merosh paroth may be more properly translated, from the naked head - the enemy shall have nothing to shield him from my vengeance; the crown of dignity shall fall off, and even the helmet be no protection against the sword and arrows of the Lord.