Jerusalem Talmud Nedarim 4:8

משנה: הַמּוּדָּר הֲנָייָה מֵחֲבֵירוֹ וְאֵין לוֹ מַה יֹאכַל הוֹלֵךְ אֵצֶל הַחֶנְװָנִי וְאוֹמֵר אִישׁ פְּלוֹנִי מוּדָּר מִמֶּנּוּ הֲנָייָה וְאֵינִי יוֹדֵעַ מַה אֶעֱשֶׂה. וְהוּא נוֹתֵן לוֹ וּבָא וְנוֹטֵל מִמֶּנּוּ. MISHNAH: If somebody is forbidden any profit from another person by a vow and he has nothing to eat, the other person goes to the grocer and tells him, X is forbidden any profit from me by a vow and I do not know what to do¹⁰¹The grocer understands that he has to acquire the money before he gives anything to X in order not to infringe on the vow.. Then he pays him and X comes and takes from him.

הלכה: הַמּוּדָּר הֲנָייָה מֵחֲבֵירוֹ וְאֵין לוֹ מַה יֹאכַל כול׳. שֶׁאֵינוֹ יָכוֹל לְהוֹצִיא מִמֶּנּוּ בַּדִּין. HALAKHAH: “If somebody is forbidden any profit from another person by a vow and he has nothing to eat,” etc. For he cannot recover from him in a court of law¹⁰²Neither the donor nor the recipient can go to court if the grocer takes the money and does not deliver since the donor cannot be more explicit if he does not want to violate his vow. Therefore, the money really becomes the grocer’s and this method is not circumventing the law..