That they may shoot in secret at the perfect: suddenly do they shoot at him, and fear not.
That they may shoot in secret at the perfect - like night murderers waylaying the unwary traveler (Psalms 10:8-9).
Suddenly do they shoot at him - when he least suspects danger.
And fear not - God and His coming judgment; cf. Psalms 64:9 on the contrary (Psalms 55:19).