What is a good source to search the origins of a saying?

The Phrase Finder is a good source to search for the origin of a saying. The website maintains origin summaries for thousands of English phrases.

The Phrase Finder site is divided into categories, which include proverbs, American phrases and phrases coined by Shakespeare. The website provides users with a search function that they use by inputting a specific phrase. Once they select a specific phrase from the results, the website gives a brief explanation of that phrase's origin. The Phrase Finder also includes references for each entry to make further research easier. It maintains a "Famous Last Words" section, which lists the final statements of well-known individuals.