That he heard the Messenger of Allah ﷺ say: "Whoever separates between a mother and her child, then Allah will separate between him and his beloved on the Day of Judgement."  

سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ مَنْ فَرَّقَ بَيْنَ وَالِدَةٍ وَوَلَدِهَا فَرَّقَ اللَّهُ بَيْنَهُ وَبَيْنَ أَحِبَّتِهِ يَوْمَ الْقِيَامَةِ