The 319th prohibition is that we are forbidden from striking [either of] our parents.

For this prohibition, too, there is no specific verse written in the Torah. Only the punishment is written,1 "Whoever strikes one's father or mother shall be put to death." The derivation of the actual prohibition against striking his father is similar to that of cursing one's father, as we explained.2 In this case, prohibition 300, which forbids striking any Jew, includes [the prohibi­tion of striking] one's father.

The Mechilta3 says, "The verse, 'Whoever strikes his father or mother,' tells us the punishment. What is the source of the actual prohibition? That comes from the verse4 [which speaks of lashing a transgressor], 'Do not go beyond the limit and give him forty lashes.' This verse teaches us a kal v'chomer:5 If even one who it is a mitzvah to strike, it is prohibited to strike him [beyond the limit], one who it is a mitzvah not to strike, certainly it is prohibited to strike."

One who transgresses this prohibition by intentionally striking his father or mother and causes bleeding, is punished by chenek [strangulation].

The details of this mitzvah are explained in the end of tractate Sanhedrin.6