במדבר, פרק ל׳, פסוק ו׳

A young unmarried woman living under her father's roof exists within a shared household, meaning her personal commitments can ripple outward and affect the entire family. When she makes a binding promise, her father possesses the unique authority to step in and cancel that obligation. This cancellation is not merely a physical prevention of her keeping the promise or a scolding for making it. Rather, it is a formal, legal removal of the prohibition [אבן עזרא, הכתב והקבלה]. To effectively lift the restriction, the father must explicitly state his intention out loud [רש״י, מזרחי, מלבי״ם].

This authority comes with a strict time limit. The father must act on the very day he learns of the vow. He cannot wait and attempt to cancel it days later [אבן עזרא, רלב״ג]. Furthermore, there is a fundamental difference between a father's authority and that of a husband. The primary approach among commentators is that a father has the power to cancel any and all types of vows his daughter makes. In contrast, a husband can only annul vows that cause his wife personal suffering or directly impact their relationship. The father's broader power stems from the fact that his daughter is an integral part of his household. Any vow she makes has the potential to impact family property or reflect upon her father's honor [העמק דבר, בכור שור, פירושן של נשים].

A central question arises regarding why the daughter would need divine forgiveness if her father successfully canceled her vow. If the restriction no longer exists, there should seemingly be no wrongdoing. The primary approach among commentators is that this refers to a situation where the father annulled the vow, but the daughter remained unaware of his action. Believing her promise was still fully binding, she intentionally chose to violate it. Even though she did not technically break any rule, since the vow had already been voided, her deliberate intention to sin requires forgiveness from God [רש״י, רלב״ג, משכיל לדוד]. Other perspectives offer different reasons for this required forgiveness. It may be necessary simply because she rushed to make a serious promise regarding matters that were not entirely in her control, as she lives under her father's authority [ספורנו]. Alternatively, God's forgiveness might only apply to actions she took after the vow was officially canceled. If she violated her promise before her father even heard about it and annulled it, the cancellation does not apply retroactively, and her earlier actions remain unforgiven [הטור הארוך, העמק דבר].

Finally, the process of canceling a vow demands absolute precision and cannot rely on mere assumptions. A daughter cannot simply assume her promise is void just because her father typically cancels her vows. Furthermore, the father's annulment must be directed specifically at her and her specific vow. If he overhears a vow and mistakenly believes his wife made it, intending to cancel it for his wife, that cancellation does not apply to the daughter [תורה תמימה, מלבי״ם].