Chapter 29
Laws Derived from Isaiah: Running, Walking, Commerce, Measuring, Reading, Speaking
SPEAKING ON SHARBATH AND YOM TOV WITH THE OBJECT OF CONDUCTING EVERYDAY AFFAIRS
58.a. The verses from Isaiah referred to in paragraph 2 above are also the source of a prohibition against the release from vows on Shabbath or Yom Tov.
58.b. A person may be released from a vow on Shabbath or Yom Tov only when it is required for Shabbath or the festival or for the purpose of a mitzva.
58.c. A person may be released in such a case, even if he could have been released before Shabbath or Yom Tov but, for some reason, failed to attend to the matter.
58.d. 1) The annulment of the vows of a small girl by her father and of a wife by her husband, on the day on which he hears of it, is always permitted.
2) This is because omission by the father or husband to annul on the day on which he hears of the vow precludes subsequent annulment. (See also Chapter 28, paragraph 83).

