ذِكْرُ الْإِخْبَارِ بِأَنَّ الْخَيْطَ الْأَبْيَضَ هُوَ الْفَجْرُ الْمُعْتَرِضُ فِي أُفُقِ السَّمَاءِ

" Eat and drink till the white streak is distinct from the dark streak," a person would take hold of a white thread and a black thread and keep on eating till he could find them distinct (in the light of the dawn). It was then that Allah, the Majestic and Great, reveiled (the words) min al-fajr (from the dawn), and then it became clear (that the word khait refers to the streak of light in the dawn).  

لَمَّا نَزَلَتْ هَذِهِ الآيَةُ { وَكُلُوا وَاشْرَبُوا حَتَّى يَتَبَيَّنَ لَكُمُ الْخَيْطُ الأَبْيَضُ مِنَ الْخَيْطِ الأَسْوَدِ} قَالَ كَانَ الرَّجُلُ يَأْخُذُ خَيْطًا أَبْيَضَ وَخَيْطًا أَسْوَدَ فَيَأْكُلُ حَتَّى يَسْتَبِينَهُمَا حَتَّى أَنْزَلَ اللَّهُ ﷻ { مِنَ الْفَجْرِ} فَبَيَّنَ ذَلِكَ  

he asked the Messenger of Allah about the verse "Until the white thread (light) of dawn appears to you distinct from the black thread (darkness of night)." He said: "It is the blackness of the night and the whiteness of the day." '  

أَنَّهُ سَأَلَ رَسُولَ اللَّهِ ﷺ عَنْ قَوْلِهِ تَعَالَى { حَتَّى يَتَبَيَّنَ لَكُمُ الْخَيْطُ الأَبْيَضُ مِنَ الْخَيْطِ الأَسْوَدِ } قَالَ هُوَ سَوَادُ اللَّيْلِ وَبَيَاضُ النَّهَارِ  

"When 'Until the white (light) thread of dawn appears distinct to you from the black thread (of night)' was revealed, the Prophet ﷺ said to me: 'That only refers to the whiteness of the day from the blackness of the night.'"  

لَمَّا نَزَلَتْ ( حَتَّى يَتَبَيَّنَ لَكُمُ الْخَيْطُ الأَبْيَضُ مِنَ الْخَيْطِ الأَسْوَدِ مِنَ الْفَجْرِ ) قَالَ لِي النَّبِيُّ ﷺ إِنَّمَا ذَاكَ بَيَاضُ النَّهَارِ مِنْ سَوَادِ اللَّيْلِ  

"إِنَّمَا ذَلِكَ سَوادُ الَّليْلِ وبياضُ النَّهَارِ" يعنى قوله تعالى: {الْخَيْطُ الْأَبْيَضُ مِنَ الْخَيْطِ الْأَسْوَدِ} ".