I know this in the version "The devil finds work for idle hands." Its meaning is, typically, that if people don't have enough to do, they may turn to mischief - or, more personally, it can be used to tell someone not to be so lazy and to find something useful to do. The intended meaning in any specific use really depends on the speaker or writer :) https://dictionary.cambridge.org/dictionary/english/devil-finds-work-for-idle-hands https://www.macmillandictionary.com/dictionary/british/the-devil-makes-finds-work-for-idle-hands https://idioms.thefreedictionary.com/the+devil+makes+work+for+idle+hands

It means that people who are not busy are more likely to get into trouble. It is often used by parents or teachers who are assigning tasks to children.