‘The devil makes work for idle hands’ is one of the numerous variants of phrase that express the idea that trouble or evil arises from not keeping busy.

The source of the proverb ‘The devil makes work for idle hands to do’ is debatable as there are so many alternative forms of expression that convey the same idea. It is certainly Christian texts of one form or another which were the first to put the proverb into print. For example, the 4th century theologian Jerome expressed the idea in his Letter 125:

Fac et aliquid operis, ut semper te diabolus inveniat occupatum.
[Do something, so that the Devil may always find you busy.]

The first version to appear in English, albeit Middle English, is in Chaucer’s Melibeus, circa 1405:

Dooth somme goode dedes, that the deuel, which is oure enemy, ne fynde yow nat vnocupied.
[Do some good deeds, so that the Devil, which is our enemy, won’t find you unoccupied.]

The same notion is repeated many times in religious texts throughout the Middle Ages but it isn’t until the 19th century that we find the proverb in the form that it is now widely used. Here’s an example from The Indicator, February 1848:

The boys are not permitted to idle away their time in the streets,… for the inhabitants firmly believe that ‘the devil finds work for idle hands to do’