Yerushalmi Gittin
If he transgressed and annulled [the divorce document]? Let us hear from the following: If he annulled, it is annulled, the words of Rabbi. Rabban Simeon ben Gamaliel says: He can neither annul it nor add to his condition. Rabban Simeon ben Gamaliel says it correctly. What is the reason of Rabbi? It is the word of the Torah that [i.e., according to Torah law] he has the power to annul, but they [the rabbis] said: He shall not annul. Can their word uproot the words of the Torah? But is it not from the Torah that one may [give] olives for oil and grapes for wine [as terumah],1 but because of robbing the [priestly] tribe they said not only that one may not give terumah [in this way] but if he transgressed and gave, his terumah is not terumah.
Notes
[Terumah is also sometimes called “heave offering” because it is heaved or hefted up when it is offered. It was one of the agricultural gifts given to the priests.—Ed.]
Published in: The Posen Library of Jewish Culture and Civilization, vol. 2: Emerging Judaism.