Ibn Abbas was informed that so-and-so, a certain wife of the Prophet ﷺ, had died. He fell down prostrating himself. He was questioned: Why do you prostrate yourself this moment? He said: The Messenger of Allah ﷺ said: When you see a portent (an accident), prostrate yourselves. And which portent (accident) can be greater than the death of a wife of the Prophet ﷺ.  

قِيلَ لاِبْنِ عَبَّاسٍ مَاتَتْ فُلاَنَةُ بَعْضُ أَزْوَاجِ النَّبِيِّ ﷺ فَخَرَّ سَاجِدًا فَقِيلَ لَهُ أَتَسْجُدُ هَذِهِ السَّاعَةَ فَقَالَ قَالَ رَسُولُ اللَّهِ ﷺ إِذَا رَأَيْتُمْ آيَةً فَاسْجُدُوا وَأَىُّ آيَةٍ أَعْظَمُ مِنْ ذَهَابِ أَزْوَاجِ النَّبِيِّ ﷺ