From 2015:
If one does not pull any punches, he speaks bluntly.
Why is this idiom phrased this way?
Is it because the motion of a punch, i.e., to speak bluntly, can be described as a push, which is the opposite of a pull, and thus to pull a punch would be to minimize the impact of the punch, i.e., to not speak bluntly?
What is the origination of this phrase?
I was pleasantly surprised how far back the history for this phrase goes.