Commento su Levitico 7:32

שוק is that limb of the right rear-leg extending from the knee-joint, the bone and blesh of which are usually sold as offal together with the head, unto the middle joint which is what is known as the סובך of the leg (the סובד is the small bone between that middle joint and the thigh-bone; consequently the שוק spoken of in connection with שלמים is the middle one of the three limbs that form an animal’s leg) (Chullin 134b).

ואת שוק הימין תתנו תרומה לכהן, from the part which belongs to the owners; we may view the priest in this instance as similar to the King’s minister who, when someone who comes to offer a gift to the king, accepts a smaller gift meant for the king’s servant in order to secure an audience with the king by the person bearing the larger gift.