Mishneh Torah — Negative Mitzvot מצוות לא תעשה, Chapter 319
The full Hebrew text of Mishneh Torah, Negative Mitzvot, Chapter 319, with English translation by Maimonides (Rambam).
שלא להכות אב ואם, שנאמר "ומכה אביו ואימו, מות יומת" (שמות כא,טו).
Not to strike one's father or mother, as [Exodus 21:15] states: "One who strikes his father or mother shall surely die."