Mishneh Torah — Negative Mitzvot מצוות לא תעשה, Chapter 133
The full Hebrew text of Mishneh Torah, Negative Mitzvot, Chapter 133, with English translation by Maimonides (Rambam).
שלא יאכל זר תרומות, שנאמר "וכל זר, לא יאכל קודש" (ויקרא כב,י).
For an unauthorized person not to partake of the terumot, as [Leviticus 22:10] states: "No unauthorized person shall eat it."