سنن نسائي
Sunan an-Nasa'i
كتاب الأيمان والنذور
The Book of Oaths and Vows
بَابُ : إِذَا نَذَرَ ثُمَّ أَسْلَمَ قَبْلَ أَنْ يَفِيَ
Chapter: If A Person Makes A Vow Then Becomes Muslim Before Fulfilling It
Hadith 3851
أَخْبَرَنَا إِسْحَاق بْنُ مُوسَى , قَالَ : حَدَّثَنَا سُفْيَانُ , عَنْ أَيُّوبَ , عَنْ نَافِعٍ , عَنِ ابْنِ عُمَرَ عَنْ عُمَرَ , أَنَّهُ كَانَ عَلَيْهِ لَيْلَةٌ نَذَرَ فِي الْجَاهِلِيَّةِ يَعْتَكِفُهَا , فَسَأَلَ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ , فَأَمَرَهُ أَنْ يَعْتَكِفَ .
It was narrated from Ibn 'Umar, that 'Umar had vowed to spend a night in 'Itikaf during the Jahiliyyah. He asked the Messenger of Allah about that, and he ordered him to perform the 'Itikaf.
