"I heard the Messenger of Allah say this on this Minbar: 'It is not permissible for a woman who believes in Allah and His Messenger to mourn for anyone who dies for more than three days, except for a husband, (for whom the mourning period is) four months and ten days.'"  

سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ عَلَى هَذَا الْمِنْبَرِ لاَ يَحِلُّ لاِمْرَأَةٍ تُؤْمِنُ بِاللَّهِ وَرَسُولِهِ أَنْ تَحِدَّ عَلَى مَيِّتٍ فَوْقَ ثَلاَثِ لَيَالٍ إِلاَّ عَلَى زَوْجٍ أَرْبَعَةَ أَشْهُرٍ وَعَشْرًا