This phrase just came up again in a discussion with family today. My parents both grew up with it from their parents and their contemporaries so 1895-1920's born. My parents are the end of the depression era. Wish I could tell from the posts above which is the definitive source. My parents are very well educated/well read and well versed in Latin (and mom in some Greek) . . . but are at a loss.

Thanks for all the comments above!!