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 reveal- ed (the words): min al-fajr. And they (the Muslims) came to know that (the word khait) refers to the night and day.  

لَمَّا نَزَلَتْ هَذِهِ الآيَةُ { وَكُلُوا وَاشْرَبُوا حَتَّى يَتَبَيَّنَ لَكُمُ الْخَيْطُ الأَبْيَضُ مِنَ الْخَيْطِ الأَسْوَدِ} قَالَ فَكَانَ الرَّجُلُ إِذَا أَرَادَ الصَّوْمَ رَبَطَ أَحَدُهُمْ فِي رِجْلَيْهِ الْخَيْطَ الأَسْوَدَ وَالْخَيْطَ الأَبْيَضَ فَلاَ يَزَالُ يَأْكُلُ وَيَشْرَبُ حَتَّى يَتَبَيَّنَ لَهُ رِئْيُهُمَا فَأَنْزَلَ اللَّهُ بَعْدَ ذَلِكَ { مِنَ الْفَجْرِ} فَعَلِمُوا أَنَّمَا يَعْنِي بِذَلِكَ اللَّيْلَ وَالنَّهَارَ  

When the verse "Until the white thread of dawn appear to you distinct from its black thread" was revealed, I took a white rope and a black rope, and placed them beneath my pillow ; and then I looked at them, byt they were not clear to me. So I mentioned it to the Messenger of Allah ﷺ. He laughed and said: Your pillow is so broad and lengthy ; that is (i.e. means) night and day. The version of the narrator 'Uthman has: That is the blackness of night and whiteness of day.  

لَمَّا نَزَلَتْ هَذِهِ الآيَةُ { حَتَّى يَتَبَيَّنَ لَكُمُ الْخَيْطُ الأَبْيَضُ مِنَ الْخَيْطِ الأَسْوَدِ } قَالَ أَخَذْتُ عِقَالاً أَبْيَضَ وَعِقَالاً أَسْوَدَ فَوَضَعْتُهُمَا تَحْتَ وِسَادَتِي فَنَظَرْتُ فَلَمْ أَتَبَيَّنْ فَذَكَرْتُ ذَلِكَ لِرَسُولِ اللَّهِ ﷺ فَضَحِكَ فَقَالَ إِنَّ وِسَادَكَ لَعَرِيضٌ طَوِيلٌ إِنَّمَا هُوَ اللَّيْلُ وَالنَّهَارُ قَالَ عُثْمَانُ إِنَّمَا هُوَ سَوَادُ اللَّيْلِ وَبَيَاضُ النَّهَارِ  

[Machine] When this verse was revealed: "And eat and drink until the white thread of dawn becomes distinct to you from the black thread (of night)" (Quran 2:187), I intended to distinguish between two headbands, one black and the other white. So I placed them under my pillow and looked at them, but I couldn't differentiate between the white and the black. When I woke up in the morning, I went to the Messenger of Allah ﷺ and informed him about what I had done. He said, "That is the whiteness of the day and the darkness of the night."  

لَمَّا نَزَلَتْ هَذِهِ الْآيَةُ {وَكُلُوا وَاشْرَبُوا حَتَّى يَتَبَيَّنَ لَكُمُ الْخَيْطُ الْأَبْيَضُ} [البقرة 187] مِنَ الْخَيْطِ الْأَسْوَدِ قَالَ عَمَدْتُ إِلَى عِقَالَيْنِ أَحَدُهُمَا أَسْوَدُ وَالْآخَرُ أَبْيَضُ فَجَعَلْتُهُمَا تَحْتَ وِسَادِي قَالَ ثُمَّ جَعَلْتُ أَنْظُرُ إِلَيْهِمَا فَلَا تُبِينُ لِي الْأَسْوَدَ مِنَ الْأَبْيَضِ وَلَا الْأَبْيَضَ مِنَ الْأَسْوَدِ فَلَمَّا أَصْبَحْتُ غَدَوْتُ عَلَى رَسُولِ اللهِ ﷺ فَأَخْبَرْتُهُ بِالَّذِي صَنَعْتُ فَقَالَ إِنْ كَانَ وِسَادُكَ إِذًا لَعَرِيضًا إِنَّمَا ذَلِكَ بَيَاضُ النَّهَارِ مِنْ سَوَادِ اللَّيْلِ  

[Machine] I said, "O Messenger of Allah, I have placed a white thread and a black thread under my pillow, but I cannot distinguish between them." He said, "You have a wide bedspread, and that night is part of the day, as Allah says, 'And eat and drink until the white thread of dawn becomes distinct to you from the black thread. Then complete the fast until the night.' And do not approach them while you are in seclusion in the mosques. These are the limits set by Allah, so do not come near them.' Thus Allah makes clear His signs to the people that they may fear Him."  

قُلْتُ يَا رَسُولَ اللَّهِ لَقَدْ جَعَلْتُ تَحْتَ وِسَادَتِي خَيْطًا أَبْيَضَ وَخَيْطًا أَسْوَدَ فَمَا تَبَيَّنَ لِي شَيْءٌ قَالَ «إِنَّكَ لَعَرِيضُ الْوِسَادِ وَإِنَّمَا ذَلِكَ اللَّيْلُ مِنَ النَّهَارِ فِي قَوْلِهِ تَعَالَى» {وَكُلُوا وَاشْرَبُوا حَتَّى يَتَبَيَّنَ لَكُمُ الْخَيْطُ الْأَبْيَضُ مِنَ الْخَيْطِ الْأَسْوَدِ مِنَ الْفَجْرِ ثُمَّ أَتِّمُّوا الصِّيَامَ إِلَى اللَّيْلِ وَلَا تُبَاشِرُوهُنَّ وَأَنْتُمْ عَاكِفُونَ فِي الْمَسَاجِدِ تِلْكَ حُدُودُ اللَّهِ فَلَا تَقْرَبُوهَا كَذَالِكَ يُبَيِّنُ اللَّهُ آيَاتِهِ لِلنَّاسِ لَعَلَّهُمْ يَتُّقُونَ}  

When the verse "Until the white thread of dawn appear to you distinct from its black thread" was revealed, I took a white rope and a black rope, and placed them beneath my pillow ; and then I looked at them, byt they were not clear to me. So I mentioned it to the Messenger of Allah ﷺ. He laughed and said: Your pillow is so broad and lengthy ; that is (i.e. means) night and day. The version of the narrator 'Uthman has: That is the blackness of night and whiteness of day. (Using translation from Abū Dāʾūd 2349)   

لَمَّا نَزَلَتْ هَذِهِ الْآيَةُ {حَتَّى يَتَبَيَّنَ لَكُمُ الْخَيْطُ الْأَبْيَضُ} مِنَ الْخَيْطِ الْأَسْوَدِ أَخَذْتُ عِقَالًا أَبْيَضَ وَعِقَالًا أَسْوَدَ فَوَضَعْتُهَا تَحْتَ وِسَادَتِي فَنَظَرْتُ فَلَمْ أَتَبَيَّنْ فَذَكَرْتُ ذَلِكَ لِلنَّبِيِّ ﷺ فَضَحِكَ وَقَالَ «إِنَّ وِسَادَكَ إِذًا لَعَرِيضٌ طَوِيلٌ إِنَّمَا هُوَ اللَّيْلُ»  

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 reveal- ed (the words): min al-fajr. And they (the Muslims) came to know that (the word khait) refers to the night and day. (Using translation from Muslim 1091b)  

لَمَّا نَزَلَتْ هَذِهِ الْآيَةُ {وَكُلُوا وَاشْرَبُوا حَتَّى يَتَبَيَّنَ لَكُمُ الْخَيْطُ الْأَبْيَضُ مِنَ الْخَيْطِ الْأَسْوَدِ} وَلَمْ يَنْزِلْ مِنَ الْفَجْرِ فَكَانَ رِجَالٌ إِذَا أَرَادُوا الصَّوْمَ رَبَطَ أَحَدُهُمْ فِي رِجْلَيْهِ الْخَيْطَ الْأَسْوَدَ وَالْخَيْطَ الْأَبْيَضَ فَلَا يَزَالُ يَأْكُلُ وَيَشْرَبُ حَتَّى يَتَبَيَّنَ لَهُ أَيُّهُمَا فَأَنْزَلَ اللهُ تَعَالَى بَعْدَ ذَلِكَ {مِنَ الْفَجْرِ} فَعَلِمُوا أَنَّمَا يَعْنِي بِذَلِكَ اللَّيْلَ وَالنَّهَارَ  

[Machine] "When the verse {And eat and drink until the white thread of dawn becomes distinct to you from the black thread [of night]} [Surah Al-Baqarah: 187] was revealed, I hung two headbands, one white and one black, under my pillow. I would wake up at night and look, but it would not become clear to me. When morning came, I went to the Prophet ﷺ and informed him. He smiled and said, 'If your pillow is thick, then it is the whiteness of the day due to the darkness of the night.'"  

لَمَّا نَزَلَتْ {وَكُلُوا وَاشْرَبُوا حَتَّى يَتَبَيَّنَ لَكُمُ الْخَيْطُ الْأَبْيَضُ} [البقرة 187] مِنَ الْخَيْطِ الْأَسْوَدِ مِنَ الْفَجْرِ الْآيَةَ عَمَدْتُ إِلَى عِقَالَيْنِ عِقَالٍ أَبْيَضَ وَعِقَالٍ أَسْوَدَ فَجَعَلْتُهُمَا تَحْتَ وِسَادَتِي فَجَعَلْتُ أَقُومُ مِنَ اللَّيْلِ فَأَنْظُرُ فَلَا يَتَبَيَّنُ لِي فَلَمَّا أَصْبَحْتُ غَدَوْتُ إِلَى النَّبِيِّ ﷺ فَأَخْبَرْتُهُ فَضَحِكَ فَقَالَ إِنْ كَانَ وِسَادُكَ لَعَرِيضًا إِنَّمَا ذَاكَ بَيَاضُ النَّهَارِ مِنْ سَوَادِ اللَّيْلِ