Mishkat al-Masabih
Ibn ‘Umar said that when ‘Umar consulted the Prophet (ﷺ) about a vow he had made in the pre-Islamic period to spend a night in devotion in the sacred mosque, he said, “Fulfill your vow.” (Bukhari and Muslim.)
وَعَنِ ابْنِ عُمَرَ: أَنَّ عُمَرَ سَأَلَ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ: " كُنْتُ نَذَرْتُ فِي الْجَاهِلِيَّةِ أَنْ أَعْتَكِفَ لَيْلَةً فِي الْمَسْجِد الْحَرَام؟ قَالَ: «فأوف بِنَذْرِك»
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