The 318th prohibition is that all people are forbidden from cursing their father or mother. The punishment for this transgression is stated explicitly in the Torah, in G‑d's statement,1 "Whoever curses his father or mother shall be put to death." The transgressor is executed by stoning.2 One who intentionally curses a parent using G‑d's Name is punished by stoning, even if the parent was already dead.

The source of the actual prohibition itself, however, is not written explicitly in the Torah.3 It does not say, "Do not curse your father," for example. But there is already a general prohibition against cursing any Jew,4 and it includes cursing both one's father and everyone else.

The Mechilta5 says, "The verse, 'Whoever curses his father or mother shall be put to death,' tells us the punishment. What is the source of the actual prohibition? The verse, 'Do not curse the judges.' If your father is a judge, he is included in [the prohibition of cursing] judges. If he is a Nasi, he is included in [the prohibition of cursing] the Nasi. If he is a regular Jew, [he is included in the prohibition of cursing a regular Jew,] as it is written, 'Do not curse the deaf.' From all three verses you can derive a general principle: just as these verses come to prohibit cursing any Jew, they also come to prohibit cursing your father."

The Sifra6 says the same as the Mechilta: "The verse,7 'Whoever curses his father or mother [shall be put to death]' tells us the punishment but not the actual prohibition. It is derived from the verse, 'Do not curse the judges.' "

The details of this mitzvah are explained in the seventh chapter of tractate Sanhedrin.8