حَدَّثَنَا عَبْدُ بْنُ حُمَيْدٍ، حَدَّثَنَا عُبَيْدُ اللَّهِ بْنُ مُوسَى، عَنْ إِسْرَائِيلَ بْنِ يُونُسَ، عَنْ أَبِي إِسْحَاقَ، عَنِ الْبَرَاءِ، قَالَ كَانَ أَصْحَابُ النَّبِيِّ صلى الله عليه وسلم إِذَا كَانَ الرَّجُلُ صَائِمًا فَحَضَرَ الإِفْطَارُ فَنَامَ قَبْلَ أَنْ يُفْطِرَ لَمْ يَأْكُلْ لَيْلَتَهُ وَلاَ يَوْمَهُ حَتَّى يُمْسِيَ وَإِنَّ قَيْسَ بْنَ صِرْمَةَ الأَنْصَارِيَّ كَانَ صَائِمًا فَلَمَّا حَضَرَهُ الإِفْطَارُ أَتَى امْرَأَتَهُ فَقَالَ هَلْ عِنْدَكِ طَعَامٌ قَالَتْ لاَ وَلَكِنْ أَنْطَلِقُ فَأَطْلُبُ لَكَ ‏.‏ وَكَانَ يَوْمَهُ يَعْمَلُ فَغَلَبَتْهُ عَيْنُهُ وَجَاءَتْهُ امْرَأَتُهُ فَلَمَّا رَأَتْهُ قَالَتْ خَيْبَةً لَكَ ‏.‏ فَلَمَّا انْتَصَفَ النَّهَارُ غُشِيَ عَلَيْهِ فَذَكَرَ ذَلِكَ لِلنَّبِيِّ صلى الله عليه وسلم فَنَزَلَتْ هَذِهِ الآيَةُ ‏:‏ ‏(‏ أُحِلَّ لَكُمْ لَيْلَةَ الصِّيَامِ الرَّفَثُ إِلَى نِسَائِكُمْ ‏)‏ فَفَرِحُوا بِهَا فَرَحًا شَدِيدًا ‏:‏ ‏(‏فَكُلُوا وَاشْرَبُوا حَتَّى يَتَبَيَّنَ لَكُمُ الْخَيْطُ الأَبْيَضُ مِنَ الْخَيْطِ الأَسْوَدِ مِنَ الْفَجْرِ ‏)‏ ‏.‏ قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ ‏.‏

Narrated Al-Bara bin 'Azib: "It was the custom among the Companions of Muhammad (PBUH), that if any of them was fasting and the food was presented but he had slept before eating, he would not eat that night, nor the following day until the evening. Qais bin Sirmah Al-Ansari fasted and came to his wife at the time of Iftar, and said to her: 'No, but I will go and bring something for you.' He worked during the day, so his eyes (sleep) overcame him. Then his wife came, and when she saw him she said: 'You shall be disappointed.' About the middle of the next day he fainted. That was mentioned to the Prophet (PBUH), so this Ayah was revealed: 'It is made lawful for you to have sexual relations with your women on the night of the fasts. So they were very happy about that. 'And eat and drink until the white thread (light) of dawn appears distinct to you from the black thread (of night). (2:187)'" Translation Not Available

Book Ref: Jamiya Tirmidhi Book 47 Hadith 2968
Web Ref:  Jamiya Tirmidhi Vol 5 Book 44 Hadith 2968