I noticed just now that if you set your character map to Wingdings and look carefully at the first row of symbols, you get three items that cannot possibly have been placed in that particular order by accident. A bell, a book, and a candle.
On a semi-related note, Snopes has an article debunking alleged anti-Semitic patterns in wingdings. For example, “NYC” in wingdings comes out as a skull and crossbones, followed by a Star of David, then by a hand giving the “thumbs up” sign. Spooky coincidence, but surely a coincidence all the same, IMO.
Microsoft has already said the Wingdings character map was “largely random”. Obviously some things(like up arrows next to down arrows) were not, but seeing other patterns are largely a result of the human tendancy to see patterns everywhere.
See obligatory Wiki link for further info. To sum up, though, it’s a phrase connected with the rite of excommunication as practiced by the Church in the Middle Ages.