2,794. A Vow Doesn't Compel Bad Situations

Hilchos Nedarim 8:12

Let’s say that person A asks person B to lend him his cow, but person B replies that the cow is unavailable. Person A responds by making an oath or a vow never to plow his field with B’s cow. If person A normally plows his field himself, he may not plow it with B’s cow, but others may do so. If he doesn’t normally plow the field himself, both he and others are prohibited to plow his field with B’s cow. The same rule applies in all comparable cases.

Hilchos Nedarim 8:13

If someone takes an oath or a vow to marry a woman, buy a house, leave with a caravan or put out to sea, we don’t make him marry, buy or depart right away. Rather, we wait until he finds a situation he likes. There was an incident in which a woman took a vow to marry whoever asked her, causing men who were not suitable for her to propose. The Sages ruled that her intention was to marry whoever asked her from among those deemed appropriate. The same principle applies in all similar situations.