Responsa for Yevamot 132:4

ותסברא נהי נמי דמחייב בגנבה ואבדה באונסיה בכחשה ובנפחת דמיה מי מיחייב הא לא דמיא אלא לסיפא ישראל ששם פרה מכהן לא יאכילנה כרשיני תרומה אבל כהן ששם פרה מישראל יאכילנה כרשיני תרומה

may not feed it on vetches of <i>terumah</i>. A priest, however, who hired a cow from an Israelite, guaranteeing him its appraised value,<span class="x" onmousemove="('comment',' Lit., 'if an Israelite appraised a cow from'. I.e., he undertook to make good to the owner any loss in the value of the animal between the date of hire and the date of the return. ');">⁹</span> may feed it on vetches of <i>terumah</i>.<span class="x" onmousemove="('comment',' The animal being regarded as the priest's own property, in respect of its feeding on terumah, owing to his responsibility for the return of its full value. Thus it follows that, though an animal would be returned in body, should its value on the day of its return be equal to that of its appraised value, it is nevertheless, owing to the priest's complete responsibility, deemed to be the priest's property so long as it remains in his possession; so also in the case of zon barzel slaves: though they would ultimately be returned to the woman in body, they are regarded, in respect of terumah, as the property of the priest, who accepted full responsibility for them, so long as they remain with him. ');">¹⁰</span> Rabbah and R. Joseph were sitting at their studies at the conclusion of R. Nahman's school session, and in the course of their sitting they made the following statement: [A Baraitha] was taught in agreement with Rab Judah; and [another Baraitha] was taught in agreement with R. Ammi. ['A Baraitha] was taught in agreement with Rab Ammi': Zon barzel slaves procure their freedom when the man,<span class="x" onmousemove="('comment',' The husband, who is regarded, in agreement with R. Ammi, as the owner of the slaves. ');">¹¹</span>

Teshuvot Maharam