Sayyiduna Umar bin Al-Khattab (may Allah be pleased with him) said: I said to the Messenger of Allah (peace and blessings be upon him), "I had made a vow during the days of ignorance, then I embraced Islam." The Messenger of Allah (peace and blessings be upon him) said: "Then fulfill your vow."
Hadith Referenceسنن دارمي / من النذور و الايمان / 2370
Hadith Gradingتحقیق (حسین سلیم أسد الدارانی):إسناده صحيح والحديث متفق عليه، [مكتبه الشامله نمبر: 2378]
Hadith Takhrijیہ حدیث صحیح اور متفق علیہ ہے۔ دیکھئے: [بخاري 6697] ، [مسلم 1656] ، [أبوداؤد 3325] ، [ترمذي 1539] ، [نسائي 3829] ، [ابن ماجه 1772، 2129]
Brief Explanation
(Explanation of Hadith 2369)
Nadhr: To make something that is not obligatory upon oneself, obligatory. And “aymaan” is the plural of “yameen,” which means oath. An example of nadhr is like someone saying, “If this boy becomes a doctor, I will perform Hajj,” or “If I profit in my business, I will give charity,” or “I will fast.” Any such nadhr, if it is not in disobedience to Allah, must be fulfilled, as is clear from the ahadith of this chapter.
Allah Ta’ala, describing the qualities of the people of Paradise, said: « ﴿يُوْفُوْنَبِالنَّذْرِ .....﴾ [الإنسان : 7]» that those who fulfill their nadhr, and also the statement of Allah Ta’ala: «﴿وَلْيُوْفُوْانُذُوْرَهُمْ .....﴾ [الحج : 29]». It should be clear that making a nadhr does not make any difference to whether a matter will occur or not; whatever Allah Ta’ala has decreed will certainly happen. That is why it is mentioned in the hadith that the only thing nadhr does is that it takes wealth out of the hand of a miserly person, because a miser only spends when some calamity befalls him.
Further details will come under Hadith number (2377).
From the above hadith, it is established that if someone made a nadhr before accepting Islam, and it is in obedience to Allah, then fulfilling it is obligatory.
Some scholars have said: Before Islam, such a nadhr has no legal status at all, so the question of fulfilling it does not arise. And when the Messenger of Allah sallallahu alayhi wa sallam told Sayyiduna Umar radi Allahu anhu to fulfill his nadhr, it was only as a recommendation (mustahabb).