What is the origin of the idiom "good gracious" and when to use it?

The origin of the idiom "good gracious" can be traced back to the use of "gracious" as an exclamation expressing surprise, often in a polite or genteel manner. "Gracious" itself is a word that has been used in the English language to convey emotions such as surprise, astonishment, or approval for several centuries. It is used to express polite surprise, astonishment, or amazement.