Pieced together from ancient legends by: unstattedCommoner
The author writes:
EDIT: After posting the original strip for this date, my mailbox was swamped by two sorts of messages: those (the vast majority) from people who didn't get the punchline, and those from people who obviously did get it and told me why the set-up was wrong. In hindsight, making a pun which relied on a detailed knowledge of ecclesiastical law was a mistake. So I've replaced it with this strip, which is (I hope) a little more obvious.
Don't worry if you missed the original; it wasn't canonical anyway.