take one's name in vain, to

take one's name in vain, to

To mention a person casually and disrespectfully. This expression, today always used jocularly, comes from the biblical commandment against blasphemy: “Thou shalt not take the name of the Lord thy God in vain” (Exodus 20:7). It was already used more lightly in the eighteenth century, when Jonathan Swift included it in Polite Conversation (1738): “Who’s that takes my name in vain?”
See also: name, take