poor as a churchmouse

Idioms  

1. Having little or no wealth and few possessions, as in She's poor as a churchmouse, so you can't expect her to donate anything. The reason for this long-used simile is unclear, but most believe that, since churches are not known for storing food, a mouse inside one would fare poorly. It has survived such earlier phrases as poor as Job. [Second half of 1600s]

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