"rush to judgment": meaning and origin

[Mark Spahn]

What does the term "rush to judgment" mean, and what is its origin?

A search on "rush to judgment definition" leads to

http://dictionary.sensagent.com/rush%20to%20judgment/en-en/

which lists this phrase as the title of a book and a movie about the
assassination of U.S. President John F. Kennedy.  I have heard these
titles all my life, but I always assumed that the phrase "rush to
judgment" must be some allusion to a famous poem or work of literature. 
Now that we have the Internet (thank, Algore!), at last I can find where
this phrase originated, possibly in some play by Shakespeare.

But the search I did just now did not turn up an answer about the origin
of this phrase.  (Or maybe I'm not searching correctly?)

But let's continue with the question, What does "rush to judgment"
mean?  Presumably it means being in a hurry to come to a judgment, but
"judgment" in what sense?  To judge where the truth lies about a
question, or to pass judgment about who are morally right and wrong in
some event?

It's remarkable that the oracular Internet is withholding its answer
about what "rush to judgment" means and where it comes from.

-- Mark Spahn (West Seneca, NY)

[Mark Spahn]

Someone succinctly and promptly (but not rushingly) comes to a judgment
about this phrase:

"I don't think it's an idiom or an allusion -- it just means being in a
hurry to come to a judgment, and since judgment could refer either to
factual or moral judgment, the phrase can refer to both."

As far as I'm concerned, that settles the matter:  my idea that it was
some preexisting phrase from literature or history was just a
missupposition.

-- Mark Spahn (West Seneca, NY)