Sahih Muslim Book - 18, Hadith - 3726

قَالَتْ زَيْنَبُ ثُمَّ دَخَلْتُ عَلَى زَيْنَبَ بِنْتِ جَحْشٍ حِينَ تُوُفِّىَ أَخُوهَا فَدَعَتْ بِطِيبٍ فَمَسَّتْ مِنْهُ ثُمَّ قَالَتْ وَاللَّهِ مَا لِى بِالطِّيبِ مِنْ حَاجَةٍ غَيْرَ أَنِّى سَمِعْتُ رَسُولَ اللَّهِ -صلى الله عليه وسلم- يَقُولُ عَلَى الْمِنْبَرِ « لاَ يَحِلُّ لاِمْرَأَةٍ تُؤْمِنُ بِاللَّهِ وَالْيَوْمِ الآخِرِ تُحِدُّ عَلَى مَيِّتٍ فَوْقَ ثَلاَثٍ إِلاَّ عَلَى زَوْجٍ أَرْبَعَةَ أَشْهُرٍ وَعَشْرًا ».

Zainab said: "Then I entered upon Zainab bint Jahsh when her brother died. She called for some perfume and put on some of it, then she said: 'By Allah, I have no need of perfume, but I heard the Messenger of Allah (s.a.w) saying on the Minbar: "It is not permissible for a woman who believes in Allah and the Last Day to mourn for more than three days for anyone who dies, except for a husband; four months and ten days."