Rashi on Deuteronomy 18:3/רש"י על דברים י״ח:ג׳

1מאת העם [AND THIS SHALL BE THE PRIESTS’ DUE] FROM THE PEOPLE — but not from the priest (i.e. if a priest slaughters animals for his own use he is exempt from giving these dues to another priest) (Sifrei Devarim 165:3; cf. Chullin 132b).

2אם שור אם שה WHETHER IT BE ONE OF THE HERD OR ONE OF THE FLOCK — this excludes an undomesticated beast (חיה).

3הזרע THE SHOULDER is the portion from the knee-joint to the shoulder-blade that is called espalte in old French (cf. Rashi on Chullin 134b).

4והלחיים THE TWO CHEEKS — together with the tongue. — Those who interpret the Bible text symbolically (cf. Chullin 134b) said: The זרוע of the animals, (termed יד in later Hebrew), became the due of the priests as a reward for the “hand’’ (יד) which Phineas, the priest, raised against the wrong-doers, as it is said. (Numbers 25:7) “and he took a javelin in his hand”; the “cheek-bones” together with the tongue are a reward for the prayer he offered, as it is said, (Psalms 106:30) “Then stood up Phineas and prayed”; והקבה AND THE MAW — as a reward for his act described thus (Numbers 25:8): “[And he thrust both of them through, the man of Israel] and the woman in her stomach (קבתה) (Chullin 134b).