Schoftim 5:2 Kommentar: Rashi, Metzudat David, Metzudat Zion & Radak

When Yisroel was inundated with breaches. When breaches befell Yisroel; when their enemies invaded them because they deserted Adonoy, and yet the people volunteered to repent—at this point, bless Adonoy for bringing deliverance.

When there was the takings of vengeance (this is the translation of, feroa peraot, according to Radak): That is to say, in that which the Holy One, blessed be He, took His vengeance through Israel - to make it appear as if it was through their strength that it was done, so that it would be glorious for them.

A matter of Vengeance as in Numbers 31:2 "you shall surely take revenge. and according to the Targum