كتاب النكاح
16
The Book of Marriage
(21)
Chapter: The prohibition of disclosing a woman's secrets
(21)
باب تَحْرِيمِ إِفْشَاءِ سِرِّ الْمَرْأَةِ ‏

Abu Sa'id al-Khudri (Allah he pleased with him) reported that Allah's Messenger (may peace be upoin him) said:

The most wicked among the people in the eye of Allah on the Day of judgment is the men who goes to his wife and she comes to him, and then he divulges her secret.
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا مَرْوَانُ بْنُ مُعَاوِيَةَ، عَنْ عُمَرَ بْنِ حَمْزَةَ الْعُمَرِيِّ، حَدَّثَنَا عَبْدُ الرَّحْمَنِ بْنُ سَعْدٍ، قَالَ سَمِعْتُ أَبَا سَعِيدٍ الْخُدْرِيَّ، يَقُولُ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ "‏ إِنَّ مِنْ أَشَرِّ النَّاسِ عِنْدَ اللَّهِ مَنْزِلَةً يَوْمَ الْقِيَامَةِ الرَّجُلَ يُفْضِي إِلَى امْرَأَتِهِ وَتُفْضِي إِلَيْهِ ثُمَّ يَنْشُرُ سِرَّهَا ‏"‏ ‏.‏
Reference : Sahih Muslim 1437 a
In-book reference : Book 16, Hadith 145
USC-MSA web (English) reference : Book 8, Hadith 3369
  (deprecated numbering scheme)