Mishnayos Nedarim Perek 4 Mishnah 7

In the case of one for whom benefit from another is forbidden by vow and who does not have anything to eat, the one from whom benefit is forbidden goes to the shopkeeper and says to him: So-and-so vowed that benefit from me is forbidden for him and I do not know what I will do. After grasping his intent, the shopkeeper gives food to the one for whom benefit is forbidden, and then the shopkeeper comes and takes payment for the food from that one who spoke to him. Similarly, if the house of one for whom benefit is forbidden by a vow was to be built, his fence to be erected, or his field to be harvested, and laborers were required but he had no money to hire them, the one from whom benefit is forbidden goes to the laborers and says to them: Benefit from me is forbidden by vow to so-and-so and I do not know what I will do. And the laborers perform those tasks with him, and come and take payment for their labor from that person who approached them.

הַמֻּדָּר הֲנָאָה מֵחֲבֵרוֹ וְאֵין לוֹ מַה יֹּאכַל, הוֹלֵךְ אֵצֶל הַחֶנְוָנִי וְאוֹמֵר, אִישׁ פְּלוֹנִי מֻדָּר מִמֶּנִּי הֲנָאָה וְאֵינִי יוֹדֵעַ מָה אֶעֱשֶׂה, וְהוּא נוֹתֵן לוֹ וּבָא וְנוֹטֵל מִזֶּה. הָיָה בֵיתוֹ לִבְנוֹת, גְּדֵרוֹ לִגְדֹּר, שָׂדֵהוּ לִקְצֹר, הוֹלֵךְ אֵצֶל הַפּוֹעֲלִים וְאוֹמֵר, אִישׁ פְּלוֹנִי מֻדָּר מִמֶּנִּי הֲנָאָה וְאֵינִי יוֹדֵעַ מָה אֶעֱשֶׂה. הֵם עוֹשִׂין עִמּוֹ, וּבָאִין וְנוֹטְלִין שָׂכָר מִזֶּה: