Nazir 2:3-4

Nazir 2:3

If they filled a cup of wine for someone and he refused it, saying that he is a nazir to it, he is a nazir. There was once a woman already under the influence of alcohol who was offered a cup and she refused it, saying she was a nazir from it. The Sages said that she only meant to prohibit it to herself like a sacrifice.

Nazir 2:4

If a person says he is a nazir on the condition that he may drink wine and be rendered ritually impure through contact with the dead, he is a nazir and these things are prohibited to him. If one claimed that he knew that there’s such a thing as nezirus but he didn’t know that a nazir is prohibited to drink wine, he is still forbidden wine, though Rabbi Shimon permits it. If he says that he knew that a nazir may not drink wine but he thought the Sages would permit him to do so because he can’t live without it, and similarly if one thought they would permit contact with the dead since one is an undertaker by trade, these things are permitted, though Rabbi Shimon prohibits them.