The Book of Marriage
Ṣaḥīḥ Muslim 3542
إِنَّ مِنْ أَشَرِّ النَّاسِ عِنْدَ اللَّهِ مَنْزِلَةً يَوْمَ الْقِيَامَةِ الرَّجُلَ يُفْضِي إِلَى امْرَأَتِهِ وَتُفْضِي إِلَيْهِ ثُمَّ يَنْشُرُ سِرَّهَا
inna min asharri an-nāsi ʿinda-Llāh manzilatan yawma al-qiyāmah ar-rajula yufḍī ilā āmraʾatihi watufḍī ilayhi thumma yanshuru sirrahā
Transliteration generated from the Arabic vowel marks
The full narration
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
Source
Ṣaḥīḥ Muslim · 3542
Ṣaḥīḥ