كتاب الصيام
13  
The Book of Fasting
(14)
Chapter: The strict prohibition of intercourse during the day in Ramadan for one who is fasting; And the obligation of offering major expiation and the definition thereof; And that it is obligatory for both the one who can afford it and the one who cannot afford it, and it remains an obligation for the one who cannot afford it until he has the means
(14)
باب تَغْلِيظِ تَحْرِيمِ الْجِمَاعِ فِي نَهَارِ رَمَضَانَ عَلَى الصَّائِمِ وَوُجُوبِ الْكَفَّارَةِ الْكُبْرَى فِيهِ وبيانها وأنها تجب على الموسر والمعسر وتثبت في ذمة المعسر حتى يستطيع
Sahih Muslim 1112 c

Abbad b. Abdullah b. Zubair reported that he had heard 'A'isha, the wife of the Messenger of Allah (ﷺ), as saying:

A person came to the Messenger of Allah (ﷺ) in the mosque during (the month of) Ramadan and said: Messenger of Allah, I am burnt, I am burnt, whereupon the Messenger of Allah (ﷺ) asked him as to what the matter was. Upon this he said: I had intercourse with my wife (in a state of fasting) Thereupon he (the Holy Prophet) said: Give charity. Upon this he said: Apostle of Allah, I swear by God, there is nothing with me (to give in charity) as I do not possess anything. He (the Holy Prophet) said: Sit down. So he sat down and he was in this very state when there came a person urging a donkey with a load of eatables upon it. The Messenger of Allah (ﷺ) said: Where is that burnt one who was just here? Thereupon the person stood up. The Messenger of Allah (ﷺ) said: Give this (eatables brought by the man) in charity. Upon this the person said: Messenger of Allah, can there be anyone else (more deserving than I)? By Allah. we are hungry, we have nothing with us. Upon this he (the Holy Prophet) said: Then eat (these eatables).
حَدَّثَنِي أَبُو الطَّاهِرِ، أَخْبَرَنَا ابْنُ وَهْبٍ، أَخْبَرَنِي عَمْرُو بْنُ الْحَارِثِ، أَنَّ عَبْدَ الرَّحْمَنِ، بْنَ الْقَاسِمِ حَدَّثَهُ أَنَّ مُحَمَّدَ بْنَ جَعْفَرِ بْنِ الزُّبَيْرِ حَدَّثَهُ أَنَّ عَبَّادَ بْنَ عَبْدِ اللَّهِ بْنِ الزُّبَيْرِ حَدَّثَهُ أَنَّهُ، سَمِعَ عَائِشَةَ، زَوْجَ النَّبِيِّ صلى الله عليه وسلم تَقُولُ أَتَى رَجُلٌ إِلَى رَسُولِ اللَّهِ صلى الله عليه وسلم فِي الْمَسْجِدِ فِي رَمَضَانَ فَقَالَ يَا رَسُولَ اللَّهِ احْتَرَقْتُ احْتَرَقْتُ ‏.‏ فَسَأَلَهُ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ مَا شَأْنُهُ ‏"‏ ‏.‏ فَقَالَ أَصَبْتُ أَهْلِي ‏.‏ قَالَ ‏"‏ تَصَدَّقْ ‏"‏ ‏.‏ فَقَالَ وَاللَّهِ يَا نَبِيَّ اللَّهِ مَا لِي شَىْءٌ وَمَا أَقْدِرُ عَلَيْهِ ‏.‏ قَالَ ‏"‏ اجْلِسْ ‏"‏ ‏.‏ فَجَلَسَ فَبَيْنَا هُوَ عَلَى ذَلِكَ أَقْبَلَ رَجُلٌ يَسُوقُ حِمَارًا عَلَيْهِ طَعَامٌ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ أَيْنَ الْمُحْتَرِقُ آنِفًا ‏"‏ ‏.‏ فَقَامَ الرَّجُلُ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ تَصَدَّقْ بِهَذَا ‏"‏ ‏.‏ فَقَالَ يَا رَسُولَ اللَّهِ أَغَيْرَنَا فَوَاللَّهِ إِنَّا لَجِيَاعٌ مَا لَنَا شَىْءٌ ‏.‏ قَالَ ‏"‏ فَكُلُوهُ ‏"‏ ‏.‏
Reference : Sahih Muslim 1112c
In-book reference : Book 13, Hadith 109
USC-MSA web (English) reference : Book 6, Hadith 2465
  (deprecated numbering scheme)