It was popularised in a Something Positive comic in 2002 (note: SP is not always SFW), and became a running joke in the online RPG community.
By 2007 it was widespread enough that it could be used as a punchline in DM of the Rings not for its outlandishness (as in the SP strip), but as a familiar line that would play into the reader’s sympathies for the beleaguered fictional DM.
It’s debatable whether PeeJee’s line is the absolute origin — it’s possibly not — but it’s the origin of the line’s spread as a piece of roleplaying culture.