Do I need to "credit" the source?
The source of a "Bite" -- mentioned in each listing -- should be acknowledged. In print, definitely. In a formal speech, yes. In informal remarks, use your judgment.
When the source lends credibility, it strengthens your soundbite.
In brief comments -- such as very short media interviews -- use your judgment.
Many metaphors have circulated so widely, evolving along the way, that it's hard to know who coined them first. We've tried.