Language:
كتاب الجنائز
23  
Funerals (Al-Janaa'iz)
(30)
Chapter: The mooring of a woman for a dead person other than her husband
(30)
باب إِحْدَادِ الْمَرْأَةِ عَلَى غَيْرِ زَوْجِهَا
Sahih al-Bukhari 1279

Narrated Muhammad bin Seereen:

One of the sons of Um 'Atiyya died, and when it was the third day she asked for a yellow perfume and put it over her body, and said, "We were forbidden to mourn for more than three days except for our husbands."

حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا بِشْرُ بْنُ الْمُفَضَّلِ، حَدَّثَنَا سَلَمَةُ بْنُ عَلْقَمَةَ، عَنْ مُحَمَّدِ بْنِ سِيرِينَ، قَالَ تُوُفِّيَ ابْنٌ لأُمِّ عَطِيَّةَ ـ رضى الله عنها ـ فَلَمَّا كَانَ الْيَوْمُ الثَّالِثُ دَعَتْ بِصُفْرَةٍ، فَتَمَسَّحَتْ بِهِ وَقَالَتْ نُهِينَا أَنْ نُحِدَّ أَكْثَرَ مِنْ ثَلاَثٍ إِلاَّ بِزَوْجٍ‏.‏
Reference : Sahih al-Bukhari 1279
In-book reference : Book 23, Hadith 40
USC-MSA web (English) reference : Vol. 2, Book 23, Hadith 369
  (deprecated numbering scheme)