The Hebrew verb nu' means to refuse, to forbid, to hinder, or to disallow. It conveys the act of restraining someone from a course of action or nullifying a vow or commitment. The word appears primarily in the context of authority exercised over vows.
This verb is central to the laws governing vows in Numbers 30, where a father or husband has the authority to annul the vows of a daughter or wife. The concept illustrates the biblical principle of delegated authority and covenantal headship, while also revealing God's gracious provision for rash or burdensome commitments to be set aside under proper authority.