Rashi on Exodus 15:7/רש"י על שמות ט״ו:ז׳

1וברב גאנך AND THROUGH THE GREATNESS OF THINE EXCELLENCY: if the hand alone crushes the spirit of the enemy, then when He raises it aloft IN THE GREATNESS OF HIS EXCELLENCY surely then HE WILL OVERTHROW THEM THAT RISE UP AGAINST HIM; and if through the greatness of His excellency alone His enemies are overthrown, how much more sure is it that when HE SENDETH FORTH THE FIERCENESS OF HIS WRATH against them IT WILL CONSUME THEM].

2תהרס means, Thou always overthrowest קמיך i. e. those that rise up against thee. And who are those who rise up against Him? They are those who rise up against Israel; and similarly it says, (Psalms 83:3, 4) “For, lo, thine enemies are in an uproar!” And what is this uproar? “against thy people they take crafty counsel”, and on this account — because they are Israel's enemies — it calls them the enemies of the Omnipresent (Mekhilta).