2,802. Is Wine Grapes? Is Oil Olives? Is Sackcloth Clothing?

Hilchos Nedarim 9:14

One who vowed not to eat grapes is permitted wine, including new wine. If he vowed prohibiting olives, he is permitted oil. If he vowed prohibiting dates, he is permitted date honey. If he vowed prohibiting grapes that bloom in the fall, he is permitted vinegar made from such grapes. If he vowed prohibiting wine, he is permitted apple wine. If he vowed prohibiting oil, he is permitted sesame oil. If he vowed prohibiting honey, he is permitted date honey. If he vowed prohibiting vinegar, he is permitted vinegar made from grapes that bloom in the fall. If he vowed prohibiting vegetables, he is permitted vegetables that grow on their own. The reason underlying all of these is that these things have specific names and when the person vowed, he used the generic term. The same rule applies in all comparable cases.

Hilchos Nedarim 9:15

If someone vows not to wear clothing, he may wear sackcloth, coarse, thick fabric, and a thick sheet that is used for protection from the elements. If he vows not to enter a house, he may not enter its attic because the attic is part of the house; if he vows not to enter the attic, he may enter the house. If he vows not to use a cot, he may use a bed; if he vows not to use a bed, he may not use a cot, since it’s like a small bed.