كتاب الطلاق
18  
The Book of Divorce
(3)
Chapter: Expiation must be offered by one who declares his wife to be unlawful for him but does not intend divorce thereby
(3)
باب وُجُوبِ الْكَفَّارَةِ عَلَى مَنْ حَرَّمَ امْرَأَتَهُ وَلَمْ يَنْوِ الطَّلاَقَ ‏‏
Sahih Muslim 1474 a

'A'isha (Allah be pleased with her) narrated that Allah's Apostle (ﷺ) used to spend time with Zainab daughter of Jahsh and drank honey at her house. She ('A'isha further) said:

I and Hafsa agreed that one whom Allah's Apostle (ﷺ) would visit first should say: I notice that you have an odour of the Maghafir (gum of mimosa). He (the Holy Prophet) visited one of them and she said to him like this, whereupon he said: I have taken honey in the house of Zainab bint Jabsh and I will never do it again. It was at this (that the following verse was revealed): 'Why do you hold to be forbidden what Allah has made lawful for you... (up to). If you both ('A'isha and Hafsa) turn to Allah" up to:" And when the Prophet confided an information to one of his wives" (lxvi. 3). This refers to his saying: But I have taken honey.
وَحَدَّثَنِي مُحَمَّدُ بْنُ حَاتِمٍ، حَدَّثَنَا حَجَّاجُ بْنُ مُحَمَّدٍ، أَخْبَرَنَا ابْنُ جُرَيْجٍ، أَخْبَرَنِي عَطَاءٌ، أَنَّهُ سَمِعَ عُبَيْدَ بْنَ عُمَيْرٍ، يُخْبِرُ أَنَّهُ سَمِعَ عَائِشَةَ، تُخْبِرُ أَنَّ النَّبِيَّ صلى الله عليه وسلم كَانَ يَمْكُثُ عِنْدَ زَيْنَبَ بِنْتِ جَحْشٍ فَيَشْرَبُ عِنْدَهَا عَسَلاً قَالَتْ فَتَوَاطَأْتُ أَنَا وَحَفْصَةُ أَنَّ أَيَّتَنَا مَا دَخَلَ عَلَيْهَا النَّبِيُّ صلى الله عليه وسلم فَلْتَقُلْ إِنِّي أَجِدُ مِنْكَ رِيحَ مَغَافِيرَ أَكَلْتَ مَغَافِيرَ فَدَخَلَ عَلَى إِحْدَاهُمَا فَقَالَتْ ذَلِكَ لَهُ ‏.‏ فَقَالَ ‏"‏ بَلْ شَرِبْتُ عَسَلاً عِنْدَ زَيْنَبَ بِنْتِ جَحْشٍ وَلَنْ أَعُودَ لَهُ ‏"‏ ‏.‏ فَنَزَلَ ‏{‏ لِمَ تُحَرِّمُ مَا أَحَلَّ اللَّهُ لَكَ‏}‏ إِلَى قَوْلِهِ ‏{‏ إِنْ تَتُوبَا‏}‏ لِعَائِشَةَ وَحَفْصَةَ ‏{‏ وَإِذْ أَسَرَّ النَّبِيُّ إِلَى بَعْضِ أَزْوَاجِهِ حَدِيثًا‏}‏ لِقَوْلِهِ ‏"‏ بَلْ شَرِبْتُ عَسَلاً ‏"‏ ‏.‏
Reference : Sahih Muslim 1474a
In-book reference : Book 18, Hadith 27
USC-MSA web (English) reference : Book 9, Hadith 3496
  (deprecated numbering scheme)