Chelek 33, Korach 3

From The Sicha, Rabbi Chaim Wolosow by R Chaim Wolosow.

Giving Terumah from the Best

The Sifrei and Talmud differ on whether giving Terumah from the finest produce is merely an ideal or an obligation. The Rebbe explains that the dispute hinges on whether this requirement is a general enhancement of a mitzvah or a unique law of Terumah itself.