Exodus – 2:13 – He went out on the second day, and behold, two Hebrew men were quarreling, and he said to the evil one, “Why are you going to strike your friend?”
Gemora: Sanhedrin 58(b): Resh Lakish said, “One who raises his hand against his friend, even though he never [actually] hits him, is still called a wicked person”. This is demonstrated by the verse “and he said to the wicked one, ‘why are you going to strike your friend?” It does not say “why have you hit your friend?” but rather “why are you going to strike your friend?”
Torah Temimah Colloquial Translation on Note #38:
In other words, even though [Moshe] only saw them quarrelling, nevertheless he still said “why will you hit your friend?” {Moshe] said this because he saw the man acting in a way that showed that he would hit his friend; namely that he had lifted his hand. Since Moshe called this person ‘wicked’ we see that one who only raises his hand against his neighbor is called ‘wicked’.
Rashi on this verse writes regarding the phrase “why will you hit your friend” and explains that ‘friend’ implies ‘equal in wickedness to you’. This statement of Rashi needs further explanation [how could one conclude from this verse that the hitter was wicked?] It appears according to the Responsum of the Mabit (Moshe ben Yosef Trani) that it is permitted to hit an evil person since they are not behaving according to the ways of our people. If that was the case, then clearly one who hits a wicked person is not called wicked. Additionally, since as we see from the previous note that the two people in this story who are quarrelling with one another are the [wicked] Datan and Aviram. If this is the case, how could Moshe call the “hitter” wicked since, indeed, he was hitting a wicked person?
The answer is that one must conclude that it would only be ok to strike a wicked person if one, himself, is [totally] righteous. However, for a wicked person to hit a wicked person is totally forbidden. Therefore, in our case, a wicked person is hitting a wicked person, it is appropriate to call him wicked!
This answers the [apparent] question regarding how Rashi could conclude that someone was wicked just because he was hitting a wicked person. [The answer is that Moshe knew it was Datan and Aviram who were fighting. The proof that the person was wicked or righteous does not lie in the fact that one is hitting an evil person.]
Look also in Choshen Mishpat Section 34: Subsection 4; there the Rema states that anyone who lifts up his hand against another become invalid for testimony in court. The reason for this according to what the Sefer Meir Eineim writes in the name of the Beis Yosef. He writes that even though [lifting up one’s hand to strike another] is forbidden biblically, nevertheless since it does not have the punishment of lashes, the prohibition of such a person giving testimony in court is only rabbinic. Also, look in the Urim V’Tumim there.
In the book רה”ז he writes that the halachic practical distinction between whether the prohibition is rabbinic or biblical relates to the requirement to publicize the guilt versus no requirement to publicize it. If the guilt is biblical it would not need to be publicized (because everyone would know that this person is not kosher to be a witness) while if the guilt is rabbinic it would require publicizing. Truly, according the previously cited opinion of the Mabit that lifting one’s hand is a biblical transgression but does not make one liable for lashes, then such a case would not require announcing because everyone would be aware of a biblical transgression. If so, according to the opinion that we wrote that this prohibition is rabbinic only because it does not have a punishment of lashes but is, in reality, a biblical prohibition – then according to all opinions, announcing would not be required.
Translator’s Note: It is interesting to note that lifting one’s hand against another seems to be a separate prohibition from the prohibition of hitting another person. Further, the Torah Temimah’s main point may be that there is no assumption of righteousness to one who is hitting an evil person. He could very well be as evil as the person he is hitting.