Jerusalem Talmud Nedarim 4.7

משנה: הַמּוּדָּר הֲנָיָיה מֵחֲבֵירוֹ לֹא יַשְׁאִילֶנּוּ וְלֹא יִשְׁאַל מִמֶּנּוּ לֹא יַלְוֶינּוּ וְלֹא יִלְוֶה מִמֶּנּוּ וְלֹא יִמְכּוֹר לוֹ וְלֹא יִקַּח מִמֶּנּוּ. אָמַר לוֹ הַשְׁאִילֵנִי פָרָתָךְ אָמַר לוֹ אֵינָהּ פְּנוּיָה. אָמַר קוֹנָם שֶׁאֲנִי חוֹרֵשׁ בָּהּ לְעוֹלָם אִם הָיָה דַרְכּוֹ לַחֲרוֹשׁ הוּא אָסוּר וְכָל אָדָם מוּתָּרִין. אִם אֵין דַּרְכּוֹ לַחֲרוֹשׁ הוּא וְכָל אָדָם אֲסוּרִין.

MISHNAH: If somebody is forbidden any profit from another person by a vow, he should not borrow from him nor ask him for anything, should not give him a loan nor take a loan for him, should not sell to him nor buy from him. If he said, lend me your cow, he says: she is not available. If he said, a qônam that I shall never plough with her, if he usually ploughs, he is forbidden, the rest of the world is permitted. If he does not usually plough, he and the rest of the world are forbidden.

הלכה: הַמּוּדָּר הֲנָיָיה מֵחֲבֵירוֹ לֹא יַשְׁאִילֶינּוּ כול׳. בְּאוֹמֵר. קוֹנָם שָׂדִי שֶׁאֵינִי חוֹרֵשׁ לְעוֹלָם. כְּאוֹמֵר. קוֹנָם שָׂדִי נֶחֱרֶשֶׁת לְעוֹלָם.

HALAKHAH: “If somebody is forbidden any profit from another person by a vow, he should not lend him,” etc. If somebody says, a qônām that I shall never plough, it is the same as if he said, a qônām that my field should never be ploughed.