Mishnah for Nedarim 84:1
אם מת לא יירשנו שאני הכא דקא א"ל בחייו ובמותו
if he dies he does not succeed him! — Here it is different, because he [explicitly] stated during his lifetime and after his death.<span class="x" onmousemove="('comment',' But otherwise it may well be that the validity of a vow ceases when its subject is no longer under the control of the maddir. ');"><sup>1</sup></span>
Mishnah Demai
Rabbi Eliezer says: a man need not designate the poor man’s tithe of demai. But the sages say: he must designate it, but he need not separate.
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