You may use a quotation in a short thank you speech in order to quote a person or text. Make sure your entire speech does not consist of a long quote. Rather, use a short quote that helps further your point to the audience.
Some ideas to consider may include quoting a famous saying about thankfulness. You may also choose to include a witty or humorous saying that makes the audience loosen up at the beginning of the speech.
When you are writing your speech, make sure you only put quotation marks around the words of the original author or speaker. When you are speaking, you do not need to use finger quotes or say the word "quote" or "quotation mark." Simply read the quote and give the name or title of the source.