صحيح مسلم
Sahih Muslim
كتاب الصيام
The Book of Fasting
باب بَيَانِ أَنَّ الدُّخُولَ فِي الصَّوْمِ يَحْصُلُ بِطُلُوعِ الْفَجْرِ وَأَنَّ لَهُ الأَكْلَ وَغَيْرَهُ حَتَّى يَطْلُعَ الْفَجْرُ وَبَيَانِ صِفَةِ الْفَجْرِ الَّذِي تَتَعَلَّقُ بِهِ الأَحْكَامُ مِنَ الدُّخُولِ فِي الصَّوْمِ وَدُخُولِ وَقْتِ صَلاَةِ الصُّبْحِ وَغَيْرِ ذَلِكَ:
Chapter: Clarifying that fasting begins at dawn, and a person may eat and other than that until dawn begins; And clarifying the dawn which has to do with the rulings concerning the beginning of fasting and the beginning of the time for the Subh Prayer, and other than that, which is the Second Dawn, which is called the True Dawn. The First Dawn, which is the False Dawn, has nothing to do with the rulings
Hadith 1091
This hadith is listed as number 2535 in Maktaba Shamila
حَدَّثَنِي حَدَّثَنِي مُحَمَّدُ بْنُ سَهْلٍ التَّمِيمِيُّ ، وَأَبُو بَكْرِ بْنُ إسحاق ، قَالَا : حَدَّثَنَا ابْنُ أَبِي مَرْيَمَ ، أَخْبَرَنَا أَبُو غَسَّانَ ، حَدَّثَنِي أَبُو حَازِمٍ ، عَنْ سَهْلِ بْنِ سَعْدٍ رَضِيَ اللَّهُ عَنْهُ ، قَالَ : " لَمَّا نَزَلَتْ هَذِهِ الْآيَةُ وَكُلُوا وَاشْرَبُوا حَتَّى يَتَبَيَّنَ لَكُمُ الْخَيْطُ الأَبْيَضُ مِنَ الْخَيْطِ الأَسْوَدِ سورة البقرة آية 187 ، قَالَ : فَكَانَ الرَّجُلُ إِذَا أَرَادَ الصَّوْمَ ، رَبَطَ أَحَدُهُمْ فِي رِجْلَيْهِ الْخَيْطَ الْأَسْوَدَ وَالْخَيْطَ الْأَبْيَضَ ، فَلَا يَزَالُ يَأْكُلُ وَيَشْرَبُ ، حَتَّى يَتَبَيَّنَ لَهُ رِئْيُهُمَا ، فَأَنْزَلَ اللَّهُ بَعْدَ ذَلِكَ مِنَ الْفَجْرِ سورة البقرة آية 187 ، فَعَلِمُوا أَنَّمَا يَعْنِي بِذَلِكَ اللَّيْلَ وَالنَّهَارَ " .
Sahl bin Sa'd (RA) said: When this verse was revealed. "Eat and drink till the white streak becomes distinct from the dark streak for you," the person who decided to observe fast tied on one of his feet a black thread and on the other a white thread. And he went on eating and drinking till he could distinguish (between their colour) on seeing them. It was after this that Allah revealed (the words): min al-fajr. And they (the Muslims) came to know that (the word khait) refers to the night and day.
