2,858. A Nazirite Vow in Error

Hilchos Nezirus 2:1

If someone makes a nazirite vow accidentally, under coercion, in order to encourage someone else, or as part of an exaggeration, he is exempt the same as is the case regarding other types of vows. If someone makes a nazirite vow and later regrets doing so, he can approach a Torah scholar and request that it be permitted. One can have a nazirite vow permitted the same way one has other vows permitted.

Hilchos Nezirus 2:2

Let’s say that someone made a nazirite vow. He went to bring his offerings, having become a nazir with the intention that he would offer them when he completes the term of his vow. However, when he goes to do so, he finds that one or all of the animals was stolen. If he took his nazirite vow before the animal was stolen, then he’s a nazir; if he took it after it was lost, stolen or died, he’s not a nazir. This would be considered making a vow in error.