The Black and White Threads (Ahadith 1634 - 1636)

Bismillah.

أُحِلَّ لَكُمْ لَيْلَةَ الصِّيَامِ الرَّفَثُ إِلَىٰ نِسَائِكُمْ ۚ هُنَّ لِبَاسٌ لَّكُمْ وَأَنتُمْ لِبَاسٌ لَّهُنَّ ۗ عَلِمَ اللَّهُ أَنَّكُمْ كُنتُمْ تَخْتَانُونَ أَنفُسَكُمْ فَتَابَ عَلَيْكُمْ وَعَفَا عَنكُمْ ۖ فَالْآنَ بَاشِرُوهُنَّ وَابْتَغُوا مَا كَتَبَ اللَّهُ لَكُمْ ۚ وَكُلُوا وَاشْرَبُوا حَتَّىٰ يَتَبَيَّنَ لَكُمُ الْخَيْطُ الْأَبْيَضُ مِنَ الْخَيْطِ الْأَسْوَدِ مِنَ الْفَجْرِ ۖ ثُمَّ أَتِمُّوا الصِّيَامَ إِلَى اللَّيْلِ ۚ وَلَا تُبَاشِرُوهُنَّ وَأَنتُمْ عَاكِفُونَ فِي الْمَسَاجِدِ ۗ تِلْكَ حُدُودُ اللَّهِ فَلَا تَقْرَبُوهَا ۗ كَذَٰلِكَ يُبَيِّنُ اللَّهُ آيَاتِهِ لِلنَّاسِ لَعَلَّهُمْ يَتَّقُونَ

"It has been made permissible for you the night preceding fasting to go to your wives [for sexual relations]. They are clothing for you and you are clothing for them. Allah knows that you used to deceive yourselves, so He accepted your repentance and forgave you. So now, have relations with them and seek that which Allah has decreed for you. And eat and drink until the white thread of dawn becomes distinct to you from the black thread [of night]. Then complete the fast until the sunset. And do not have relations with them as long as you are staying for worship in the mosques. These are the limits [set by] Allah , so do not approach them. Thus does Allah make clear His ordinances to the people that they may become righteous." [2: 187]

Ibn Kathir says in his tafsir:
These Ayat contain a relief from Allah for the Muslims by ending the practice that was observed in the early years of Islam. At that time, Muslims were allowed to eat, drink and have sexual intercourse only until the `Isha' (Night) prayer, unless one sleeps before the `Isha' prayer. Those who slept before `Isha' or offered the `Isha' prayer, were not allowed to drink, eat or sexual intercourse sex until the next night. The Muslims found that to be difficult for them.
Volume 3, Book 31, Number 139:
Narrated Al-Bara:
It was the custom among the companions of Muhammad (sallallaahu `alayhi wasallam) that if any of them was fasting and the food was presented (for breaking his fast), but he slept before eating, he would not eat that night and the following day till sunset.
Qais bin Sirma-al-Ansari (radiallaahu `anhu) was fasting and came to his wife at the time of Iftar (breaking one's fast) and asked her whether she had anything to eat. She replied, "No, but I would go and bring some for you." He used to do hard work during the day, so he was overwhelmed by sleep and slept. When his wife came and saw him, she said, "Disappointment for you." When it was midday on the following day, he fainted and the Prophet (sallallaahu `alayhi wasallam) was informed about the whole matter and the following verses were revealed: "You are permitted To go to your wives (for sexual relation) At the night of fasting." So, they were overjoyed by it. And then Allah also revealed: "And eat and drink Until the white thread Of dawn appears to you Distinct from the black thread (of the night)." (2.187)

Volume 3, Book 31, Number 140:
Narrated 'Adi bin Hatim (radiallaahu `anhu):
When the above verses were revealed: 'Until the white thread appears to you, distinct from the black thread,' I took two (hair) strings, one black and the other white, and kept them under my pillow and went on looking at them throughout the night but could not make anything out of it. So, the next morning I went to Allah's Apostle (sallallaahu `alayhi wasallam) and told him the whole story. He explained to me, "That verse means the darkness of the night and the whiteness of the dawn."

Volume 3, Book 31, Number 141:
Narrated Sahl bin Saud (radiallaahu `anhu):
When the following verses were revealed: 'Eat and drink until the white thread appears to you, distinct from the black thread' and of dawn was not revealed, some people who intended to fast, tied black and white threads to their legs and went on eating till they differentiated between the two. Allah then revealed the words, 'of dawn', and it became clear that meant night and day.
I've always found this incident regarding `Adi bin Hatim (radiallaahu `anhu) very cute! It goes to say how some of us are quite literal in understanding things. Not that we're to be blamed. :P
On the other hand, there's an important lesson in it for us: the companions weren't always correct in their interpretation of Quranic ayaat or Ahadith. We'll always find differences of opinions among companions, and when we do, we should go for the most correct and favored opinion. And just because a companion reached an incorrect conclusion doesn't mean he was less intelligent or had weak imaan, na`oodhu billah! It only proves that they were human beings like us, but far better than us. If we were there, we would've made fun of `Adi (radiallaahu `anhu). But we don't find any reports of companions or the Prophet (sallallaahu `alayhi wasallam) laughing at him or making him feel bad about what he did. Such were the chosen people. <3