Sahih Muslim
The Book of Marriage (Kitab Al-Nikah)
Book Number: 008 / Hadith Number: 3370
Abu Sirma al-Khudri (Allah he pleased with him ) reported Allah's Messen- ger (may peace be upon him) as saying: The most important of the trusts in the sight of Allah on the Day of judgment is that a man goes to his wife and she goes to him (and the breach of this trust is) that he should divulge her secret Ibn Numair narrates this hadith with a slight change of wording.