Responsa for Nedarim 54:9

<big><strong>מתני׳</strong></big> נודרין להרגין ולחרמין ולמוכסין שהיא תרומה אף על פי שאינו תרומה שהן של בית המלך אף על פי שאינן של בית המלך בית שמאי אומרים בכל נודרין

— Here it is different, because he had declared, 'These rights shall be void.'<span class="x" onmousemove="('comment',' This is a stronger declaration than e.g., 'I will not claim my rights'; hence it is valid. ');">⁹</span> Now the law is: an <i>asmakta</i> does give a legal claim, providing that no unavoidable accident supervened and that a formal acquisition was made<span class="x" onmousemove="('comment',' The conceding party formally ceded his rights. This was symbolically effected by one giving an article, e.g., a scarf, to the other. ');">¹⁰</span> at an authoritative <i>Beth din</i>.<span class="x" onmousemove="('comment',' Rash and Maim.: an ordained Beth din; Ran: a Beth din with the power to enforce its decisions. ');">¹¹</span> <b><i>MISHNAH</i></b>. ONE MAY VOW TO MURDERERS,<span class="x" onmousemove="('comment',' I.e., robbers who kill if their demands are not granted. ');">¹²</span> ROBBERS,<span class="x" onmousemove="('comment',' Rashi, Ran, Rosh and Tosaf. all interpret this as private robbers. Jast.: official oppressors. These are less desperate than murderers, and do not kill if their demands are refused. ');">¹³</span> AND PUBLICANS THAT IT [THE PRODUCE WHICH THEY DEMAND] IS <i>TERUMAH</i>, EVEN IF IT IS NOT,<span class="x" onmousemove="('comment',' This vow is to save it from their hands, as terumah is forbidden to a zar, q.v. Glos. — It is remarkable that even murderers and robbers are assumed to respect the prohibition of terumah! ');">¹⁴</span> OR THAT IT BELONGS TO THE ROYAL HOUSE, EVEN IF IT DOES NOT. BETH SHAMMAI MAINTAIN: ONE MAY MAKE ANY FORM OF VOW,

Teshuvot Maharam