The commonly used phrase ‘speak of the devil’ is actually a shortened version of a longer phrase: ‘speak of the devil and he doth appear’. It refers to the experience of talking about a person who then, coincidentally, shows up. However, this wasn’t always its intended meaning.
As is the case for many idioms, this phrase has been around for hundreds of years. Its origin can be traced back to 16th century Latin and Old English texts. The earliest recorded reference is in Giovanni Torriano’s ‘Piazza Universale’ from 1666: “The English say, Talk of the Devil, and he’s presently at your elbow.” That was at a time when mentioning the devil’s name was thought to rouse the devil’s attention and bring about terrible luck.
It wasn’t until around the 20th century that this saying took on the more lighthearted meaning that we understand today.