Mishneh Torah — Negative Mitzvot מצוות לא תעשה, Chapter 148
The full Hebrew text of Mishneh Torah, Negative Mitzvot, Chapter 148, with English translation by Maimonides (Rambam).
שלא יאכל זר בשר קודשי קודשים, שנאמר "וזר לא יאכל, כי קודש הם" (שמות כט,לג).
For an unauthorized person not to eat the meat of the sacrifices of the highest order of sanctity, as [Exodus 29:33] states: "An unauthorized person shall not partake of them, for they are holy."