Short answer
Yes. A valid nadhr (vow) to do an act of worship for Allah, such as 'If I pass, I will fast three days', becomes wajib when its condition happens. A vow to do something sinful must not be kept. Making vows is not encouraged, but once made, a valid one must be fulfilled.
A nadhr is valid when it is for Allah and is an act of worship of a kind that is itself wajib, such as salah, fasting, charity or sacrifice. Fulfilling it is then wajib. A vow to commit a sin, or a vow to a grave or saint, is invalid and must not be carried out.
Other madhhabs
- Shafi'i
- Any recommended act of worship can be vowed, not only kinds that have a wajib counterpart.
- Hanbali
- A vow to do something sinful is not kept, but the person owes the kaffarah of an oath.
Explanation
A nadhr is when you make something obligatory on yourself for Allah, usually tied to a wish: 'If my mother recovers, I will give 500 dollars in charity.' The Quran praises believers who fulfil their vows, and the Prophet ﷺ said: whoever vows to obey Allah, let him obey Him, and whoever vows to disobey Allah, let him not disobey Him.
Even so, he discouraged vows. He said a vow does not change what is decreed; it only gets something out of a miser. In other words, do good freely, without bargaining with Allah. If you have already made a valid vow, though, you must keep it.
Points from the Hanafi school:
- What can be vowed: salah, fasting, sadaqah, i'tikaf, sacrifice and similar acts that have a wajib form. Vowing to do a merely permitted thing, like 'I'll eat pizza', is not a nadhr. The act must also be worship in itself, not only a means to it (such as wudu), and not something already fard on you, such as the five daily prayers.
- Place and person: if you vowed to pray in a certain mosque or give to a certain poor man, you may pray elsewhere or give another poor person.
- Who eats it: food or money from a nadhr is for the poor. You and those you are obliged to support may not eat from it.
- Vague vows: 'I owe Allah a vow' without naming anything requires the kaffarah of an oath.
- Vows to saints or graves: haram, and the vow is void.
If you can no longer do what you vowed, for example because of permanent illness, or you are unsure what your words meant, ask a mufti with the exact wording. See also kaffarah for breaking an oath.
Ask a mufti about your own case. This answer explains the general ruling. When the details of your situation matter, as they do here, ask a qualified mufti and give them the full facts. Where to ask a scholar.
The evidence
Quran, Surah Al-Insaan 76:7
يُوفُونَ بِٱلنَّذْرِ وَيَخَافُونَ يَوْمًۭا كَانَ شَرُّهُۥ مُسْتَطِيرًۭا ﴿٧﴾
They [are those who] fulfill [their] vows and fear a Day whose evil will be widespread.
Fulfilling vows is a quality of the righteous.
Quran, Surah Al-Hajj 22:29
ثُمَّ لْيَقْضُوا۟ تَفَثَهُمْ وَلْيُوفُوا۟ نُذُورَهُمْ وَلْيَطَّوَّفُوا۟ بِٱلْبَيْتِ ٱلْعَتِيقِ ﴿٢٩﴾
Then let them end their untidiness and fulfill their vows and perform Tawaf around the ancient House."
Allah commands vows to be fulfilled.
Sahih al-Bukhari 6696
Sahih... من نذر أن يطيع الله فليطعه ومن نذر أن يعصيه فلا يعصه ...
"Whoever vows to obey Allah, let him obey Him; whoever vows to disobey Allah, let him not disobey Him."
A vow of worship must be kept and a vow of sin must not.
Sahih al-Bukhari 6608
Sahih... إنه لا يرد شيئا وإنما يستخرج به من البخيل ...
"It does not turn anything back; it only gets something out of the miser."
Vowing is discouraged, since it does not change decree.
Sahih Muslim 1645
Sahih... كفارة النذر كفارة اليمين ...
"The expiation of a vow is the expiation of an oath."
The basis for paying oath kaffarah for an unspecified vow.
Where the ruling is recorded
- al-Hidaya, Kitab al-Ayman, chapter on vows. Conditions of a valid nadhr and when it becomes binding.
- Radd al-Muhtar (Ibn Abidin), Kitab al-Sawm, section on vows. Vows to saints and graves are void; the vowed place or person is not binding.
- al-Mughni (Ibn Qudama), Kitab al-Nudhur. The Hanbali view on kaffarah for a vow of sin.
Checked by our team. For a more accurate answer to your own situation, consult a scholar. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.