(46) باب تُحِدُّ الْمُتَوَفَّى عَنْهَا زَوْجُهَا أَرْبَعَةَ أَشْهُرٍ وَعَشْرًا
Narrated Humaid bin Nafi`:
Zainab bint Abu Salama told me these three narrations: Zainab said: I went to Um Habiba, the wife of the Prophet (ﷺ) when her father, Abu- Sufyan bin Herb had died. Um ,Habiba asked for a perfume which contained yellow scent (Khaluq) or some other scent, and she first perfumed one of the girls with it and then rubbed her cheeks with it and said, "By Allah, I am not in need of perfume, but I have heard Allah's Messenger (ﷺ) saying, 'It is not lawful for a lady who believes in Allah and the Last Day to mourn for a dead person for more than three days unless he is her husband for whom she should mourn for four months and ten days.'"
Reference: Sahih al-Bukhari 5334
In-book reference: Book 68, Hadith 79
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 7, Book 63, Hadith 251