Gists are short blurbs of texts or paragraphs that summarize the main point of an argument or larger idea. The term also serves as a synonym for the grounds of a legal argument. I grabbed this from Merriam-Webster’s Dictionary.
Gist was borrowed from the Anglo-French legal phrase laccion gist (“the action lies/is based [on]”) in the 17th century, and it was originally used in law as a term referring to the foundation or grounds for a legal action without which the action would not be legally sustainable.