What is the origin of the idiom "take one's name in vain" and when to use it?

The idiom "take one's name in vain" has its origins in religious and biblical language. It is derived from the Ten Commandments, a set of moral and religious principles given in the Bible, specifically in the book of Exodus and the book of Deuteronomy. The commandment that includes this phrase is traditionally worded as "Thou shalt not take the name of the Lord thy God in vain." It is used to describe the act of using someone's name, especially the name of a deity or God, in a disrespectful or irreverent manner. It is often used in religious or moral contexts, but it can also be applied more broadly to discourage the careless or disrespectful use of anyone's name or reputation.