(Mishnah): The following are choked - one who wounds his father or mother; one who kidnaps a Yisrael; a Zaken Mamrei [who rebels] against Beis Din; a false Navi, or one who prophesizes in the name of idolatry; one who has Bi'ah with a married woman; Edim Zomemim who convicted a Bas Kohen for adultery, or one who had adultery with her (even though she is burned).

One who wounds his father or mother is liable only if he made a wound.

In this respect, cursing is more stringent than hitting. One is liable for cursing [a parent] after death, but not for hitting after death.

(Gemara) Question: Which Lav forbids wounding one's father or mother? "Arba'im Yakeno Lo Yosif."

Someone that it is a Mitzvah to lash him, one is commanded not to lash him (more than required). Someone that it is not a Mitzvah to lash him, all the more so one is commanded not to lash him!