Q From Aileen Kelly, Australia: What is the origin of giving someone the sack or sacking them? None of my dictionaries are any help on this.
A The strangest thing about this colloquial expression is how ancient it is. Though recorded in English only from early in the nineteenth century, it’s very much older in both French and Dutch.
In 1611, Randall Cotgrave recorded a French equivalent, On luy a donné son sac in his French-English dictionary and explained it as “he hath his passport given him (said of a servant whom his master hath put away)”. Clearly, the expression was even older, though it has since died out in French in that form. A Dutch form den zak krijgen was recorded even earlier.
The usual explanation is that a workman almost always had his own tools, which were often very valuable. It’s argued that presenting a workman with a sack to carry them away in, either figuratively or literally, was a well-understood signal of dismissal. It sounds too much like an explanation created in desperation for us to accept it uncritically, but I can find no other suggestion.