Fig. It's because you are wicked that you have to work hard. (Usually jocular.) A: I can't seem to ever get all my work done. B: No rest for the wicked.
Perpetual torment. We are told in Isaiah 57:21 that “there is no peace, saith my God to the wicked.” The phrase is often said as “no rest for the weary” and heard as a mild complaint in labor-intensive situations.