Mishneh Torah — Positive Mitzvot מצוות עשה, Chapter 143
The full Hebrew text of Mishneh Torah, Positive Mitzvot, Chapter 143, with English translation by Maimonides (Rambam).
ליתן מן הבהמה לכוהן הזרוע והלחיים והקיבה, שנאמר: "ונתן, לכוהן, הזרוע" (דברים יח,ג).
To give a priest the shankbone, the jaw, and the maw from an animal [which is slaughtered], as [Deuteronomy 18:3] states: "And you shall give the priest the shankbone...."