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 1090
This hadith is listed as number 2533 in Maktaba Shamila
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ ، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ إِدْرِيسَ ، عَنْ حُصَيْنٍ ، عَنْ الشَّعْبِيِّ ، عَنْ عَدِيِّ بْنِ حَاتِمٍ رَضِيَ اللَّهُ عَنْهُ ، قَالَ : لَمَّا نَزَلَتْ حَتَّى يَتَبَيَّنَ لَكُمُ الْخَيْطُ الأَبْيَضُ مِنَ الْخَيْطِ الأَسْوَدِ مِنَ الْفَجْرِ سورة البقرة آية 187 ، قَالَ لَهُ عَدِيُّ بْنُ حَاتِمٍ : يَا رَسُولَ اللَّهِ إِنِّي أَجْعَلُ تَحْتَ وِسَادَتِي عِقَالَيْنِ : عِقَالًا أَبْيَضَ وَعِقَالًا أَسْوَدَ ، أَعْرِفُ اللَّيْلَ مِنَ النَّهَارِ ، فَقَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ : " إِنَّ وِسَادَتَكَ لَعَرِيضٌ ، إِنَّمَا هُوَ سَوَادُ اللَّيْلِ ، وَبَيَاضُ النَّهَارِ " .
'Adi bin Hatim (RA) reported that when (this verse) was revealed: "Until the white streak of the dawn becomes distinct from the dark streak" (ii. 187) Adi bin Hatim said: Messenger of Allah, verily I keep underneath my pillow two strings, one white and the other black, by which I distinguish night from dawn. Upon this the Messenger of Allah (ﷺ) said: Your pillow seems to be very large. For the word khait implies the blackness of the night and the whiteness of the dawn.
