أَخْبَرَنَا هَنَّادُ بْنُ السَّرِيِّ، عَنْ وَكِيعٍ، عَنْ شُعْبَةَ، قَالَ حَدَّثَنِي حُمَيْدُ بْنُ نَافِعٍ، عَنْ زَيْنَبَ بِنْتِ أُمِّ سَلَمَةَ، قَالَتْ أُمُّ حَبِيبَةَ سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ " لاَ يَحِلُّ لاِمْرَأَةٍ تُؤْمِنُ بِاللَّهِ وَالْيَوْمِ الآخِرِ تَحِدُّ عَلَى مَيِّتٍ فَوْقَ ثَلاَثَةِ أَيَّامٍ إِلاَّ عَلَى زَوْجٍ أَرْبَعَةَ أَشْهُرٍ وَعَشْرًا " .
It was narrated that Zainab bint Umm Salamah said: "Umm Habibah said: 'I heard the Messenger of Allah say: It is not permissible for a woman who believes in Allah and the Last Day to mourn for anyone who dies for more than three days, except for a husband; (she mourns for him for) four months and ten (days)." Translation Not Available
Book Ref: Sunan An Nisai Book 27 Hadith 3500
Web Ref: Sunan An Nisai Vol 4 Book 27 Hadith 3530