Break thou the arm of the wicked and the evil man; i.e. "break thou his strength; take away his ability to work evil to others." Seek out his wickedness till thou find none; rather, require his wickedness.
The verb is the same as that used in the last clause of Psalms 10:13. The wicked man had said in his heart, "Thou wilt not require;" the psalmist calls on God, not only to require, but to require to the uttermost.
Seek out, be says, require, and bring to judgment, all his wickedness—every atom of it—until even thy searching eye can find no mere to require, requite, and punish.