The Book Pertaining to the Merits of the Companions (Allah Be Pleased With Them) of the Holy Prophet (May Peace Be Upon Him) (Kitab Al-Fada'il Al-Sahabah)
Muslim :: Book 31 : Hadith 6066
Anas b. Malik reported that Allah's Apostle (may peace be upon him) told me something secretly. I informed none about that and Umm Sulaim asked me about it, but I did not tell her even.