Related for Gittin 3:7
הַמַּלְוֶה מָעוֹת אֶת הַכֹּהֵן וְאֶת הַלֵּוִי וְאֶת הֶעָנִי לִהְיוֹת מַפְרִישׁ עֲלֵיהֶן מֵחֶלְקָן, מַפְרִישׁ עֲלֵיהֶן בְּחֶזְקַת שֶׁהֵן קַיָּמִין, וְאֵינוֹ חוֹשֵׁשׁ שֶׁמָּא מֵת הַכֹּהֵן אוֹ הַלֵּוִי אוֹ הֶעֱשִׁיר הֶעָנִי. מֵתוּ, צָרִיךְ לִטֹּל רְשׁוּת מִן הַיּוֹרְשִׁין. אִם הִלְוָן בִּפְנֵי בֵית דִּין, אֵינוֹ צָרִיךְ לִטֹּל רְשׁוּת מִן הַיּוֹרְשִׁים:
If one lent money to a Cohein, a Levite, or a pauper, to deduct the amount from their share of (the tithe), he deducts it on the assumption that they are alive; and he need not apprehend that the Cohein or the Levite died or that the pauper became wealthy. [When he separates terumah, he sells it and keeps the money for himself for his loan to the Cohein; and he keeps the first-tithe and the poor-tithe and eats it for his loan to the Levite and to the pauper (but from the first-tithe he separates terumath-ma'aser for the Cohein.) And if he is wont to give his terumoth and ma'aseroth to this Cohein, or Levite, or pauper from whom he borrowed, he need not invest them with his ma'aseroth and terumoth through another, but he takes them for himself immediately after he tithes them. But if he is wont to give his terumoth and ma'aseroth to others, he cannot keep them for his loans until he first invests another with them, and then takes them back for his loan.] If they (the Cohein, Levite, or pauper) died, he must receive permission from the heirs [who inherited land on which the creditor has a claim. He must receive their permission to collect this debt through these terumoth and ma'aseroth. For they might desire to receive their gifts and to repay the debt of their testator from elsewhere.] If he lent them before beth-din, he need not receive permission from the heirs.