הלכה על סנהדרין 33:5

And the Sages reduced one of the forty in the understanding of the negative commandment of 'do not increase.' So wrote Rambam, may his memory be blessed, (Mishneh Torah, The Sanhedrin and the Penalties within their Jurisdiction 17:1), and it is a wonder [to say such a thing], according to [that which is written in] the Gemara. And this prohibition is a warning to hit anyone of Israel. And if we are warned about not striking the sinner, is it not all the more so with all other people? And the sages, may their memory be blessed, prevented us from even hinting to strike. They said (Sanhedrin 58b), "Anyone who raises his hand against his fellow to hit him is called an evildoer, as it states (Exodus 2:13), 'and he said to the evildoer, "Why do you strike your fellow?"'"