It comes from the book of Isaiah in the Bible, Chapters 48 and 57. The original is usually translated as "no peace for the wicked," but what you found is the common form today.
Literally, it means that the wicked will never find peace (or rest), but will be tormented eternally. (Many consider it to refer to the Christian concept of hell.) It is sometimes used an a sarcastic sense, but for us to say anything about that, you will have to provide more context from the article in which you found it.
I only know the original "no peace for the wicked". It's most often, if not always, said in reference to oneself, self-deprecatingly (somewhat as "I cannot afford to rest, so therefore I must be wicked, according to the proverb". The speaker, of course, does not believe this). The sense is, for example after a break from work, "I have things to do"; "I must get on (with my work)". Often accompanied by a sigh or an "Oh well..".
See my post above, which you may have missed. Your context exactly fits the usual usage of this phrase. It means "I cannot rest; I have things to do". The reference to wickedness is purely a reference to the biblical quotation, and does not actually refer to any real wickedness in the situation.
I my family it was / is used fairly frequently.
A: You are going to write that letter aren't you.
B: (who really wanted to let things go, and is trying to procrastinate) Oh dear, there is no rest for the wicked is there. Yes I will this afternoon.