After a sun eclipse: bedposts and curtains in sex life and warfare
The phrase in a/the twinkling of a bedpost (with the archaic variant bedstaff) means the same as in a twinkling of an eye, that is, “very quickly,” because twinkle, when used metaphorically, refers to a rapid movement. Agreed: eyes and stars twinkle, but bedposts don’t, and here is the rub.